The Bb/G/F key convertible (swtichable) version of CarolBrass Saxy Trumpet is delivered with a Bb Saxy Trumpet, a set of G key tuning slide kit and a set of F key kit. With the G key & F key kits, you can lower the natural harmonic (Known as "pitch") of this Saxy Trumpet from Bb to G major, and even to F major without transposition. "You buy one, then gain three."