It made of silicone, easy to carry it,waterproof,anytime and anywhere, ... demo mode, lesson mode, volume control mode.1.pucker punction of electronic keyboard2.External phone output3.External DC input 4.100 ... weight body, but also by its superior sound quality ,Built-in stereo speaker system which is good for concert ,You can ... players, or people on the go 37 keys roll'in up silicone electronic piano