Vandoren LC54PP Bass Clarinet Ligature And Plastic Cap (Pewter)The new M O ligature combines the lightness of the legendary Masters ligature and the clamping efficiency of the OPTIMUM ligature. the M O ligature allows an optimum vibration of the reed and a crisp articulation. Lightweight. Easy to set up. Quick and symmetrical tightening with a unique double track screw mechanism. Inverted tightening with only 2 small contact points on the reed.