A slideridoo, as they are sometimes called, made of plastic... ahem, fiberglass that sounds quite good for its' price and the material it is built of. The main selling point of course is that you can change the pitch of it, so you can jam along to what ever instruments you happen to play with. There are just a couple of issues. One of them being is that the mouthpiece can feel a bit sharp, so you might need some wax to make it softer. Another one is that it actually has quite an awful chemical smell when slid wide open. But otherwise quite a nice instrument.