Yamaha Trombone Mouthpiece 51B

Yamaha Model 51B The 51 rim with a relatively shallow cup. Powerful sound. Similar to a Bach 5G, but with a shallower cup - or a Schilke 51B. Inner Diameter = 25.23mm. Contour = standard. Thickness = standard. Cut Depth = semi-shallow. Throat = 6.92mm. Backbone = semi-wide.