Series 13 American Pitch- Profile 88 Vandoren has developed the "13 Series" mouthpiece specifically for American clarinetists using A440 Pitch. Four model have been originally developed w/ specific facings to this series: the M13, M13 Lyre, M15 and M30 mouthpieces. The "13 Series" range also encompasses other models (traditional facings): 5RV, 5RV Lyre, B45, B40 and B40 Lyre. M13- More open, the same qualities as the M13, easier to play in the upper register. Its facing gives it a particularly pure sound.