Bb Clarinet Mouthpieces Boehm system Vandoren СМ4158 М13 Lyra "13 Series" with beak versions Profile 88. Easier to play in the upper register. Its facing gives it a particularly pure sound.
The “13 series” mouthpiece was developed specifically for American clarinetists using A440 pitch.
A=440. The Beak: Profile 88. Tip Opening: 102- (1/100mm). Medium Long Facing. Works best with Vandoren #3,5 - #4,5 Reeds.