The Tuba Exchange Model 1300S is a non compensating, 4 piston Bb Euphonium with a .570" graduated bore, large shank mouthpiece receiver and 11" bell. These are old stock with minor scratches, as well as finish imperfections (plating flaws). Includes mouthpiece and TE euphonium gig bag (no hard case), but still a GREAT deal at this price!