Premium silicone, for all the right reasons. It's hypoallergenic and easy to clean (top-rack dishwasher safe). It warms quickly to your body's temperature and retains heat. It's firm yet flexible, durable, and has an amazingly life-like feel. Odor-free and phthalate-free. What could be better? It's made to the exacting and consistent standards of Doc Johnson, the industry's leader.