BBb-Tuba, front action, 4 valves , Model 1271, Bell diameter 420 mm (16,535 inch), piston valves, front action, nickel silver trimmings, Bore of valve section conical 18,8 - 19,6 mm (0,74 - 0,772 inch), brass body, Material of mouthpipe nickel silver, Mouthpiece TU17, lacquered