A player in doubt as to the conformity of equipment used to play the game should consult The R&A or USGA. A manufacturer should submit to The R&A or USGA a sample of the equipment to be manufactured for a ruling as to whether it conforms with the Equipment Rules. The sample becomes the property of The R&A or USGA for reference purposes. If a manufacturer fails to submit a sample, or, having submitted a sample, fails to await a ruling before manufacturing and/or marketing the equipment, the manufacturer assumes the risk of a ruling that the equipment does not conform to the Equipment Rules.Where a club, ball, device, other equipment, or part thereof, is required to meet a specification within the Equipment Rules, it must be designed and manufactured with the intention of meeting that specification.This point can be illustrated using Part 2, Section 2a, which states, in part, that “The shaft must be straight”. According to the above clause, this means that manufacturers are expected to design shafts with the intention that they will be straight. However, taking into consideration the materials commonly used to make shafts and the manufacturing techniques involved, it is not always possible for them to be perfectly straight. As long as it is clear that the shaft is designed and manufactured with the intention of being straight, a reasonable level of tolerance is given when evaluating shafts for conformance.The R&A and USGA reserve the right, at any time, to change the rules relating to clubs, balls, devices and other equipment and make or change the interpretations relating to these Equipment Rules. For up to date information, please contact The R&A or USGA, or refer to our respective websites. Any design of a club, ball, device or other equipment that is not covered by the Equipment Rules, which is contrary to the purpose and intent of the Rules or that might significantly change the nature of the game, will be ruled on by The R&A and USGA.The dimensions and limits contained in the Equipment Rules are given in the units by which conformance is determined. An equivalent imperial/metric conversion is also referenced for information, calculated using a conversion rate of 1 inch = 25.4 mm and 1 oz = 28.35g.The vast majority of people who play golf assume that when they buy items of golf equipment, they conform with the Equipment Rules. To help prevent non-conforming equipment from appearing in the marketplace or from being used, The R&A and USGA offer an equipment testing and evaluation service to manufacturers, and encourage manufacturers to submit drawings, descriptions, and/or prototype samples of new product to the appropriate governing body as early in the development process as possible, prior to mass production and distribution, in order to avoid potentially costly consequences should The R&A or USGA determine that the product does not conform. Additionally, this process helps to protect golfers from unwittingly obtaining non-conforming equipment for use under the Rules of Golf. While this procedure works most of the time, there are occasions when non-conforming equipment is sold in the marketplace. That, combined with the fact that many golfers like to make their own modifications to clubs (see Rule 4-1a. Clubs Allowed in Making a Stroke), make the Equipment Rules an important tool for all concerned.