Vandoren M/O Series ligatures combine the lightweight construction of the legendary Masters Series ligature with the highly efficient tightening of the OPTIMUM Series ligature. This advanced ligature allows the reed to freely vibrate for crisp tonal articulation. M/O Series Clarinet Ligatures are available for Bb, Eb, alto, and bass clarinets in black, silver-plated, and pewter. The Bb ligature is also available gold-plated. Lightweight Easy to set up Quick and symmetrical tightening with a unique double-track screw mechanism Two small contact points only on the reed with an inverted tightening