Echoes through you! The Echo is made of 100% medical grade Silicone. The hypoallergenic dong measures 6" in length and has a diameter of 1.5". The base of the dildo allows it to fit most harnesses. A removable 1.625" x .5" multi-speed bullet can be placed in the base to send powerful vibrations through the Echo. Tantus has used only the highest grade of Silicone so you can keep your play safe. The Silicone is bleachable, boilable, and dishwasher safe. With no smell or taste, it really stands above the rest. Listen to the sounds of satisfaction!