Tennis Federation. 4. THE RACKET Rackets, which are approved for play under the Rules of Tennis, must comply with the specifications in Appendix II. The International Tennis Federation shall rule on the question of whether any racket or prototype complies with Appendix II or is otherwise approved, or not approved, for play.
https://www.itftennis.com/media/2510/2020-rules-of-tennis-english.pdf