Crystal Premium Glass Eggs Pink Strips are great for Kegel exercises. The entire Crystal collection is made of 100% hand-blown, premium Borosilicate glass. These items are of the highest quality, and represent the most vibrant and durable glass products available today. Crystal items can be heated or cooled to personal taste. These artistic gems are made from 100% Borosilicate glass, and are designed to bring pleasure to pubococcygeus muscle or PC muscle exercises. Once inserted, they will help strengthen the Kegel muscle, while providing rippling effects of stimulation. At 1.75 inches long by 1 inch wide in size, these eggs are a delicious, yet discreet item. Crystal premium glass eggs include a silk storage bag and a detailed instruction manual. Manual outlines PC muscle exercises designed to give pleasure and maintain healthy muscle control. Weight: 3.40 ounces. New Sensations Sex Toys.