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/cooled to personal taste. No matter the size. our Crystal glass plugs are a stunning display of erotic art. This beautiful design is available in 3 different sizes. with 2 color options available per size.The medium Crystal premium glass plugs are 3 (80mm) tall.