Key of F/Bb/F alto, .472" bore, 12-1/8" yellow brass bell with medium-large bell throat, gold brass mouthpipe, 4 hollow rotary valves, dual plane valve on 4th rotor for smooth key changes, nickel silver inner and outer slides, unlacquered brass enhances natural sonic characteristics, engraved valve caps, handmade construction. Includes case, mouthpiece, and premiere rotor oil. All Yamaha wind instruments come with a limited 5-year warranty.