The pBone Mouthpiece made from 100% Plastic is designed specifically for small shank trombones. It is ideal for a beginner or student player looking for an inexpensive alternative to a metal mouthpiece. With a pBone not necessarily required, the plastic mouthpiece will work immediately in winter conditions and does not require the player to warm the mouthpiece. Ideal for outdoor carolling or bands this mouthpiece is a size 11C.