Yamaha Trombone 51c4 Mouthpiece L/shank

Yamaha Model 51C4. Shallower cup than the 51. Plenty of volume and power. Solid tone throughout the instrument?s range. Similar to a Bach 5G, but with a slightly shallower cup. Inner Diameter = 25.23mm. Contour = semi-flat. Thickness = standard. Cut Depth = standard. Throat = 6.92mm. Backbone = semi-wide.