Fever Student BBb Sousaphone NICKEL AVA2450-NK A top-quality BBb brass sousaphone at a price that won't empty the school budget! Made with extra support bracing to add durability. Key of B/Bb .640" bore, 24" bell, 3 valves, extra support bracing, lacquered brass finish. Includes silver-plated mouthpiece and hard case. Features: Key of B/Bb, 640" bore, 24" bell, 3 valves, Extra support bracing for added durability, Lacquered brass finish, Silver-plated mouthpiece, Includes hard case.