U.S. Patent No.D995672S1. The VolcanoGrip Grip Trainer is a patented attachment that helps players build a correct, consistent grip. It's already on the market, selling at volcanogrip.com and in a retail pickleball store in Jacksonville, FL. It works for pickleball, tennis, racquetball, padel, and golf. I'm open to a licensing deal with royalties, or an outright sale. Samples, sales history, and manufacturing details are available. Send me a message and let's talk.