F-Tuba, bell 42 cm, 5 valves , Model 81B (181 5V), Bell diameter 420 mm (16,535 inch), rotary valves, combined goldbrass-nickel silver valve section, spiral spring system, Bore of valve section conical 19,6 - 21,2 mm (0,772 - 0,835 inch), goldbrass body, nickel silver wreath, Material of mouthpipe goldbrass, Mouthpiece TU19, lacquered