F-Tuba, bell 42 cm, 4 valves , Model 81A (181 4V), Bell diameter 420 mm (16,535 inch), rotary valves, nickel silver trimmings, spiral spring system, Bore of valve section conical 20,4 - 21,2 mm (0,803 - 0,835 inch), brass body, nickel silver wreath, Material of mouthpipe nickel silver, Mouthpiece TU19, lacquered