Luv Inc. In the business of Love. A kegel ball set that gradually increases for training. The soft ribbed silicone adds texture for pleasure. 100% silicone. Rattling ball in every kegel ball. Ergonomic design. Waterproof. Hypoallergenic. Single Ball- 4.7 inches overall x 1.4 inches diameter Double Ball - 6.8 inches overall x 1.4 inches diameter.