SUMMERS, Justice:
Plaintiffs pende implant failed and had to be surgically removed. He brought this products liability suit against the manufacturer. The jury reached a defendant’s verdict and the plaintiff appeals, raising three issues for our resolution: (1) whether the jury was properly instructed on the law of “unavoidably unsafe products” as that rule appears in Comment k of the Restatement of Torts, (2) whether evidence of a doctor’s prior acts were admissible under 12 O.S. § 2404(B), and (3) whether a witness was properly qualified to testify as an expert. We affirm.
Robert Tansy became impotent due to an adverse reaction to prescription medication for a neurological disorder. He went to a urologist, Dr. Barnes, and after trying several alternatives, decided on a penile implant. Dr. Barnes discussed with Tansy the different implants available. Eventually Tansy and Dr. Barnes decided on the OmniPhase prosthesis because of its cosmetic appeal. The OmniPhase implant was based on new technology and was manufactured and distributed by the defendant Dacomed. The literature on the OmniPhase implant stated that it had a relatively low failure rate as compared to others on the market, and was unique in its design and use of metal cables.
Tansy experienced no difficulty with the implant for a period of time. But less than two years after the implantation of the device, he developed a knot on the side of his penis. Upon returning to Dr. Barnes, it appeared that the cables contained in the prosthetic device had broken, and immediate removal was necessary to prevent further bodily damage. Tansy underwent surgery to remove the prosthesis.
The evidence showed that the cables in the device failed due to fatigue. Apparently the metal cables rub against one another when the device is activated. Over a period of time the cables break. Dacomed was aware of the possibility of cable fatigue. The plaintiffs expert testified that the design was defective, and could have been made safer by using larger cables and by avoiding metal rubbing on metal when it was activated. However, the leading engineer for Dacomed stated that these other options had been tested, and that the one chosen was the best option available under current knowledge. [884]*884The evidence also showed that the Omni-Phase implant was an important step forward in penile implant technology, as it was unique in its capability to “impart rigidity or flaecidity on demand.” It also had a much lower failure rate than the inflatable type of implant.
The jury was given instructions on the plaintiffs theory of manufacturer’s product liability. It was also instructed, over the objection of the plaintiff, as follows:
If you find that the penile prosthesis manufactured by Dacomed Corporation was unavoidably unsafe, in that it was a prescription medical device which was incapable at the time of manufacture of being made totally safe, it is not unreasonably dangerous if it was marketed with proper directions for use, or included adequate warnings of potential dangers or contraindications.
The jury returned a verdict in favor of Da-comed.
Tansy appealed and the Court of Appeals upheld the jury’s verdict, holding that the instruction was appropriate. We granted certiorari to address the “unavoidably unsafe product” question, and now affirm the jury-ver diet.
COMMENT K AND ITS APPLICABILITY TO MEDICAL DEVICES
Section 402A of the Restatement (Second) of Torts sets forth the elements of products liability. When a manufacturer sells a product in a defective condition which makes it unreasonably dangerous, and the product causes physical harm to the user of the product, the manufacturer can be held responsible for the damage caused if the product reaches the user without substantial change. We adopted manufacturers’ products liability in Kirkland v. General Motors Corporation, 521 P.2d 1353 (Okla.1974), as a legitimate cause of action in Oklahoma.
The purpose behind manufacturers’ products liability is to protect the ultimate consumer from the burden of loss caused by a defective product:
It is to the public interest to discourage the marketing of products having defects that are a menace to the public. If such products nevertheless find their way into the market it is to the public interest to place the responsibility for whatever injury that may occur upon the manufacturer ... [T]he manufacturer is best situated to provide such protection.
Kirkland, 521 P.2d at 1362, quoting Escola v. Cocar-Cola Bottling Co., 24 Cal.2d 453, 150 P.2d 436 (1944). The manufacturer is in a position of control over the manufacture and testing of the product. Further, the manufacturer is the party most likely to be capable of handling the financial burden caused by a defective product.
Comment k of Section 402A speaks to products described as “unavoidably unsafe.” It seeks to strike a balance between manufacturer responsibility and the encouragement of research and development of new products. In certain instances it is in the public interest to allow products to be marketed which are unsafe, because the benefits of the product justify its risks. Comment k reads as follows:
k. Unavoidably unsafe products. There are some products which, in the present state of human knowledge, are quite incapable of being made safe for their intended and ordinary use. These are especially common in the field of drugs. An outstanding example is the vaccine for the Pasteur treatment of rabies, which not uncommonly leads to very serious and damaging consequences when it is injected. Since the disease itself invariably leads to a dreadful death, both the marketing and the use of the vaccine are fully justified, notwithstanding the unavoidable high degree of risk which they involve. Such a product, properly prepared, and accompanied by proper directions and warning, is not defective, nor is it unreasonably dangerous. The same is true of many other drugs, vaccines and the like, many of which for this very reason cannot legally be sold except to physicians, or under the prescription of a physician. It is also true in particular of many new or experimental drugs as to which, because of lack of time and opportunity for sufficient medical experience, there can be no assurance of [885]*885safety, or perhaps even of purity of ingredients, but such experience as there is justified the marketing and use of the drug notwithstanding a medically recognizable risk. The seller of such products, again with the qualification that they are properly prepared and marketed, and proper warning is given, where the situation calls for it, is not to be held to strict liability for unfortunate consequences attending their use, merely because he has undertaken to supply the public with an apparently useful and desirable product, attended with a known but apparently reasonable risk.
While products liability law seeks to protect the public from unreasonably dangerous products, Comment k seeks to protect another facet of the public’s interest — that of having available new products whose benefits are great enough as to justify associated risks. It protects certain manufacturers who develop new products which at the time of manufacture are incapable of being made totally safe, and shields certain products by classifying them as “unavoidably unsafe” rather than as “defective.” Hill v. Searle Laboratories, 884 F.2d 1064 (8th Cir.1989). Public policy favors the development and marketing of new beneficial drugs and devices because they can save lives, reduce pain and improve the quality of life. Hufft v. Horowitz, 4 Cal.App.4th 8, 5 Cal.Rptr.2d 877 (4 Dist.1992). “Strict liability might prove to be a dis-incentive to manufacturers to develop and market beneficial drugs because of ‘fear of large adverse monetary judgments’ and the expense of strict liability insurance, costs that could ‘place the cost of medication beyond the reach of those who need it most.’ ” Hufft, 5 Cal.Rptr.2d at 381 quoting Brown v. Superior Court, 44 Cal.3d 1049, 245 Cal.Rptr. 412, 751 P.2d 470 (1988).
Most courts which have considered the question have found that Comment k applies to medical devices, especially those which are implanted in the human body. See Hufft v. Horowitz, 4 Cal.App.4th 8, 5 Cal.Rptr.2d 377 (4th Dist.Ct.App.1992) and Harwell v. Amer. Med. Systems, Inc., 803 F.Supp. 1287 (M.D.Tenn.1992) (penile prosthesis was protected under Comment k); Snyder v. Mekhjian, 244 N.J.Super. 281, 582 A.2d 307 (A.D. 1990) aff'd 125 N.J. 328, 593 A.2d 318 (1991) (blood transfused into patient causing AIDS was covered under Comment k); Perfetti v. McGhan, 99 N.M. 645, 662 P.2d 646 (Ct.App. 1983) (Comment k applied to a breast implant); Allen v. G.D. Searle, 708 F.Supp. 1142 (D.Ore.1989), McKee v. Moore, 648 P.2d 21 (Okla.1982) and Terhune v. AH. Robins, 90 Wash.2d 9, 577 P.2d 975 (1978) (Comment k applied to an IUD); Phelps v. Sherwood, 836 F.2d 296 (7th Cir.1987) and Brooks v. Medtronic Inc., 750 F.2d 1227 (4th Cir.1984) (pacemaker and heart catheter covered under Comment k). But see Hawkinson v. AH. Robins Co., 595 F.Supp. 1290 (D.Colo. 1984) (Daikon Shield); Coursen v. AH. Robins, 764 F.2d 1329 (9th. 1985) (Daikon Shield). See 70 A.L.R.4th 16 (1989) for a complete review of these cases. This Court, in McKee v. Moore, 648 P.2d 21 (Okla.1982), applied Comment k to an implanted IUD, holding that it may be an “unavoidably unsafe” product under Comment k, and thus not “defective.” Id. at 23.
In Hufft v. Horowitz, supra, and Harwell v. American Med. Systems, Inc., supra, penile implants were held to be within the protection of Comment k. The Hufft court held that these type of devices “serve the salutary purposes of restoring a degree of normalcy to the lives of those who suffer organic dysfunctions and an impaired quality of life.” Id. 5 Cal.Rptr.2d at 383.
Comment k serves as an affirmative defense when the product is incapable of being made safe under present technology, but the social need for the product warrants its production. Hill, 884 F.2d at 1068; Larsen v. Pacesetter Systems, Inc., 74 Haw. 1, 837 P.2d 1273 (1992) (pacemaker did not fall under Comment k because it was capable of being made safer at the time of its manufacture). “[T]he design must be as safe as the best available testing and research permits.” Toner v. Lederle Laboratories, 112 Idaho 328, 732 P.2d 297, 306 (1987) cert. denied 485 U.S. 942, 108 S.Ct. 1122, 99 L.Ed.2d 282 (1988). There must be at the time of manu-fácture and distribution “no feasible alternative design which on balance accomplished the subject product’s purpose with a lesser risk.” Id. 732 P.2d at 306. The manufactur[886]*886ers of the product are held to the knowledge and experience of experts in their fields. Id. 732 P.2d at 307; White v. Wyeth Laboratories, Inc., 40 Ohio St.3d 390, 533 N.E.2d 748, 753 (1988); Feldman v. Lederle Laboratories, 97 N.J. 429, 479 A.2d 374, 386-87 (1984) cert. denied — U.S. -, 112 S.Ct. 3027, 120 L.Ed.2d 898 (1992).1
The defense is available-only when the product is properly manufactured and contains adequate warnings. Id.; McPheron v. Searle Laboratories, Inc., 888 F.2d 31, 33 (5th Cir.1989); Harwell v. Amer. Med. Systems, Inc., supra; Allen v. G.D. Searle & Co., 708 F.Supp. 1142, 1149 (D.Ore.1989). The Comment k defense does not apply when the product is defective due to faulty manufacturing or inadequate warnings. Grundberg v. Upjohn Co., 813 P.2d 89, 92 (Utah 1991).
Several courts have held that a risk-utility analysis must also be employed before Comment k will bar recovery under products liability. See Hufft, 5 Cal.Rptr.2d at 383; Kociemba v. G.D. Searle, 680 F.Supp. 1293 (D.Minn.1988); Toner v. Lederle Laboratories,. 112 Idaho 328, 732 P.2d 297 (1987). The benefits of the product must outweigh its risks. Toner, 732 P.2d at 306; Kearl v. Lederle Laboratories, 172 Cal.App.3d 812, 218 Cal.Rptr. 453 (Div. 4 1985). “This weighing process should consider the value of the benefit, the seriousness of the risk, and the likelihood of both.” Toner, 732 P.2d at 306, citing Belle Bonfils Memorial Blood Bank v. Hansen, 665 P.2d 118 (Colo.1983). Comment k implicitly, by its language, requires this risk-benefit analysis; the Comment speaks of a product’s utility justifying its risks.2
Following the guidance of our prior case law as well as that of other jurisdictions, we hold that Comment k can apply to medical devices, particularly those which are implanted. The Comment does not provide blanket protection for all medical devices. Rather it applies only as an affirmative defense in those eases in which the following criteria are met: (1) the product is properly manufactured and contains adequate warnings, (2) its benefits justify its risks, and (3) the product was at the time of manufacture and distribution incapable of being made more safe. See Allen v. G.D. Searle Co., 708 F.Supp. 1142, 1149 (D.Ore.1989); Goursen v. AH. Robins Co., 764 F.2d 1329, 1338 (9th Cir.1985). These issues are generally questions for the jury’s determination, and must be determined on a case-by-case basis. See Coursen, 764 F.2d at 1338; Kociemba, 680 F.Supp. at 1300; White, 533 N.E.2d at 752. Because it is an affirmative defense, the defendant bears the burden of proof. Id. 680 F.Supp. at 1338.
Here, Tansy does not question the proper manufacture of the product. As for the warning requirement, we first note that Oklahoma has adopted the learned intermediary doctrine. McKee, 648 P.2d at 24. This doctrine permits a manufacturer to warn the physician, rather than the ultimate consumer, of the problems associated with the product. Here, neither party questions the doctrine’s application to the present circumstances. Instead, Tansy urges that the doctor was not given sufficient information to evaluate the product. Tansy claims that Dr. Barnes was given incorrect information regarding the expected lifetime of the OmniPhase prosthesis. Dr. Barnes testified that a Dacomed repre[887]*887sentative told him the device would last for 10,000 activations. However, the brochure distributed by Dacomed made no claims as to its expected lifetime and also stated that certain movements of the prosthesis could affect its reliability. The documentation also showed that various complications could require the surgical removal of the device. Although the evidence was conflicting, there was evidence to support the defendant’s assertion that adequate warnings were given. It was then a question of fact for the jury to determine. We find that the first criteria for Comment k’s application was met.
The next question is whether the product’s benefits justify its risks. The OmniPhase prosthesis was a step forward in penile implant technology. Implants on the market before the OmniPhase had failure rates as high as 40%. The studies on the OmniPhase implant revealed a failure rate of between 3.7% and 6%. Furthermore, the cosmetic appearance of other implants required that tight or binding clothing be avoided. The OmniPhase implant permitted a man to wear the trousers of his choice. As stated in Hufft, these implants help restore a degree of normalcy to the lives of those who suffer sexual dysfunction. We agree that a jury could reasonably conclude that the benefits of the OmniPhase prosthesis justified the risks associated with its implantation.
As for the last criteria, Tansy argues that the OmniPhase could have been made safer. Dr. Barnes testified that a larger cable could have been used to avoid the cable fatigue. However, the Dacomed engineer testified that a thicker cable was tried, but its results were unsatisfactory because it decreased the ability of the penis to appear flaccid. The engineer also testified that no suitable alternative existed to avoid the “metal rubbing on metal” problem, as no other materials were of sufficient strength. A jury question was thus presented on this, the final criteria applicable.
Tansy urges that Comment k does not operate to protect products which are “defective”, but only offers protection when the use of the product causes “side effects.” He urges that in McKee v. Moore, supra, Comment k applied because the product, an IUD, was functioning properly for its intended purpose of preventing pregnancy, but that it caused unwanted side effects. He claims it is only these side effects which were protected by Comment k.
We disagree. First, in McKee the facts showed that the IUD had not functioned as intended to prevent pregnancy. Thus, McKee lends no support for to Tansy’s assertion that “side effects” are protected while “defects” are not. Furthermore, the eases are clear that Comment k is meant to apply when a product is unavoidably unsafe because of a defect. In fact, courts hold that Comment k applies to “re-classify” a product from “defective” to “unavoidably unsafe.” Hill, 884 F.2d at 1068. As it expressly states, Comment k can apply to all consequences caused by the use of the device. The example used in Comment k illustrates this point. The Rabies vaccine could be considered defective because of its life-threatening side effects. However, it is the intent of Comment k to re-classify this product as unavoidably unsafe so that the public may have access to such a valued and necessary vaccine.
As for the instruction given regarding Comment k, the only question remaining is whether the instruction was adequate to inform the jury of the law. We will not reverse a judgment where the instructions when viewed as a whole fairly presented the applicable law as raised by the pleadings and evidence. Dutsch v. Sea Ray Boats Inc., 845 P.2d 187 (Okla.1992); Root v. Kamo Elec. Coop Inc., 699 P.2d 1083 (Okla.1985). Here Comment k was the basis of the defendant’s theory of defense. Since we have held that Comment k is applicable to this particular medical device, the trial court was correct to given an instruction explaining it.
Tansy urges that the instruction did not adequately explain to the jury the legal definition of “unavoidably unsafe.” The instruction stated that a product was unavoidably unsafe if it was a “prescription medical device which was incapable at the time of manufacture of being made totally safe-” Although we agree that the instruction could have been worded in more detail, it was [888]*888sufficient to apprise the jury of the applicable law. In the future instructions regarding Comment k should include the conditions to its applicability as we have set out in this opinion.
THE EVIDENCE OF THE DOCTOR’S PREVIOUS IMPLANTATION
In his next assignment of error, Tansy asserts that the trial court erred in permitting evidence, over objection, regarding a prior incident in which Dr. Barnes is alleged to have improperly implanted the OmniPhase. Tansy complains that the admission of this evidence was in violation of 12 O.S.1991 § 2404(B). Section 2404(B) reads:
B. Evidence of other crimes, wrongs, or acts is not admissible to prove the character of a person in order to show action in conformity therewith. It may, however, be admissible for other purposes, such as proof of motive, opportunity, intent, preparation, plan, knowledge, identity or absence of mistake or accident.
Dacomed urges that this evidence was admissible as falling within one of the enumerated exceptions of Section 2404(B), namely that of knowledge. Dacomed claims that the evidence showed Dr. Barnes’ knowledge of how to determine whether it had been implanted correctly, and knowledge of how to conceal an error.
Character evidence, as mentioned in section 2404, involves a “generalized description of one’s disposition in respect to a general trait such as honesty, temperance or carefulness....” Whinery, Oklahoma Evidence: Commentary on the Law of Evidence, § 15.03, quoting Frase v. Henry, 444 F.2d 1228, 1332 (10th Cir.1971). The restrictions on its admissibility apply in criminal and civil cases. Title 12 O.S.1991 § 2103.3 Under Section 2404(B), character evidence is dealt with through the application of a specialized relevancy inquiry. Id. at 311. Only that evidence of other acts which is relevant for some reason other than showing action in conformity with character is admissible.
While this Court has not interpreted Section 2404(B), other courts have found that this section permits testimony of other acts to show knowledge in civil cases. McCormick on Evidence, § 197 (4th Ed.1992). For example, in United States v. O’Brien, 601 F.2d 1067 (9th Cir.1979), evidence was admitted under Section 404(B) of the Federal Rules of Evidence.4 The evidence showed continued acceptance by the defendant of state and federal funds to which he was not entitled. The government introduced this evidence in a prosecution for making false statements to the Social Security Administration to rebut the defendant’s claims of inadvertent mistake, and asserted that it showed the defendant’s knowledge that he was making false statements. On appeal the Ninth Circuit upheld the trial court’s decision to admit the evidence. In so holding the court stated that before evidence can be admitted under Rule 404(B), the “court must weight its probative value against the potential prejudice.” Id. at 1070; see also United States v. Bi-Co Pavers, Inc., 741 F.2d 730 (5th Cir. 1984).
In Gutierrez-Rodriguez v. Cartagena, 882 F.2d 553 (1st Cir.1989), the First Circuit was asked to resolve the question of whether evidence of prior complaints against a police officer were admissible during a trial in which the officer was sued for civil rights violations. The court relied on a two part test to make its decision: (1) was the evidence of prior bad acts introduced for a legitimate purpose, and (2) should it be suppressed because of substantial prejudice? The court held that the evidence was admissible not to show the tendencies of the defendant, but to show that his supervisors had knowledge of his poor performance record. See also In re Air Crash in Bali 684 F.2d 1301 (9th Cir.1982) cert. denied 493 U.S. 917, 110 S.Ct. 277, 107 L.Ed.2d 258 (1989) (evidence of a pilot’s prior poor flight record was [889]*889admissible to show that the airline had notice of pilot’s inabilities).5
In this case Dacomed asserts that the evidence was introduced to show the doctor’s knowledge of how to insert the device, how to determine whether it was correctly implanted and how to disguise any professional error. One of Daeomed’s theories was that the failure of the OmniPhase was due to an incorrect implantation by Dr. Barnes. In the prior implantation Dacomed had requested, and Dr. Barnes had taken, x-rays of the prosthesis before removal. Dacomed’s witness testified that it required such x-rays before removal or the warranty would not be honored. Those x-rays in the other case had revealed that one of the pieces of the prosthesis had been implanted upside down, and had caused the device to fail.
In Tansy’s case, Dr. Barnes failed to take x-rays before removal as requested by Da-comed. These x-rays would have shown whether the device was correctly implanted. Dacomed’s introduction of the prior incident was argued to be relevant to show that Dr. Barnes knew Dacomed’s procedure of requiring x-rays before removal of the device, and knew that if the device had been improperly implanted, failure to take x-rays would have eliminated evidence of such mistake. Dr. Barnes claimed that he did not take x-rays because after his examination of Tansy, he thought it was obvious that the cable had broken, and that immediate removal was necessary. He stated that he saw no need for the additional time or cost in taking an x-ray. When the implant was removed, Dr. Barnes’ diagnosis of a broken cable proved to be correct.
Under Gutierrez-Rodriguez, we first look to whether the admission of this evidence was for a legitimate purpose and showed something other than propensity. In our case this is a difficult and very close question. We conclude Dacomed had reason to seek admission of the evidence to show that Dr. Barnes was familiar with the procedures required by Dacomed for removal of the Omni-Phase. The prior incident shows that Dr. Barnes had been faced with a problem with the OmniPhase before the incident with Tansy, and had been instructed to take x-rays of the device while it remained implanted. The Doctor’s knowledge of Dacomed’s requirements are thus relevant to this theory of Dacomed.
The second part of the test is a balancing test very similar to that under Section 2403.6 We must determine whether the probative value of the evidence outweighs its prejudicial effect. Our concern is that the evidence could have been improperly interpreted by the jury to show a propensity on the part of the doctor to implant these improperly, and to cover up such mistake. As the reviewing court, however, we will not overturn the trial court’s ruling under Section 2403 unless there is a clear abuse of discretion. See Gabus v. Harvey, 678 P.2d 253, 256 (Okla.1984); Jones v. Stemco Mfg. Co., 624 P.2d 1044 (1981). The evidence was relevant; there was also a risk of prejudice with regard to the jury. But we do not find [890]*890an abuse of discretion in allowing the testimony.7 There was no other evidence that this implantation by Dr. Barnes was incorrect, and the jury clearly observed that the device failed because a cable broke.
THE EXPERT WITNESS
As his final assignment of error, Tansy claims that it was error to permit the Director of Clinical and Regulatory Affairs of Dacomed to testify as an expert “medical” and “engineering” witness. Mary Wilen, the Director, is a licensed practical nurse. She worked as a nurse for several years, and was later employed as a research nurse to carry out clinical studies. At Dacomed, her duties include setting up clinical studies and selecting doctors to be in those studies. She was involved in the clinical study conducted on the OmniPhase prosthesis, and has extensive experience in conducting clinical research. She was also the person who handled any problems presented by doctors during or after the implantation of the device.
At trial Wilen testified that on an occasion prior to Tansy’s, Dr. Barnes had implanted an OmniPhase device incorrectly. In her testimony, she explained how the device should be implanted. She testified as to the ordinary procedures followed by Dacomed when there is a complaint. Lastly, she testified as to how the clinical studies were conducted, and that the studies showed a 3.77% fail rate with the OmniPhase.
The statements made by Wilen were within her base of knowledge and expertise. She did not testify as to the proper engineering or designing of the prosthesis. She simply testified to facts and opinions that were within her realm of knowledge as the Director of Clinical Affairs.
The trial court’s decision regarding the qualifications of an expert will not be reversed unless there is a clear abuse of discretion. Gabus, 678 P.2d at 257. The trial court gave the jury an instruction which stated that the weight to give expert testimony was entirely up to the jury. The jury was aware of her qualifications and of her position within Dacomed. They could give her testimony whatever weight they determined appropriate. Again, we find no abuse of discretion in allowing her to testify.
CONCLUSION
The opinion of the Court of Appeals is vacated, although we reach the same conclusion reached there. The judgment for Defendant rendered in the District Court based on the jury verdict is affirmed.
LAVENDER, V.C.J., and HARGRAVE, OPALA, ALMA WILSON and WATT, JJ., concur.
HODGES, C.J., and KAUGER, J., concur in result.
SIMMS, J., concurs in part, dissents in part.