BBb-Tuba, compensating, 4 valves , Model 1280 compensating, 4 (3R/1L), Bell diameter 500 mm (19,685 inch), piston valves, compensating, top action, nickel silver trimmings, waterkey on 1st and 3rd valve, Bore of valve section conical 19,6 - 20,4 mm (0,772 - 0,803 inch), brass body, Material of mouthpipe nickel silver, Mouthpiece TU33, lacquered