Key of F single. Taper of the mouthpipe improves response and intonation while the wrap allows a more comfortable hand position and smoother air flow. Nickel silver inner and outer slides ensure better fit and less chance of corrosion than brass. Tapered valves offer long life without air leakage. Rich warm tone, superb flexibility, easy response, and accurate intonation make it a great musical investment. .472" bore, 12-1/8" bell diameter, medium bell throat, gold brass mouthpipe, 3 solid rotors, string lever action, yellow brass body and bell, clear epoxy lacquer finish, 32C4 mouthpiece, yellow brass rotor casing, and redesigned lighter ABS case. All Yamaha wind instruments come with a limited 5-year warranty.