Laskey 90D This is a mouthpiece for bass trombone. Specifications (quoted from the official website) Inner rim diameter: 29.00mm Outer rim diameter: 39.73mm Throat diameter: 7.93mm Backbore diameter: 11.00mm I bought this but didn't use it much because it was a little too big for me. There are some scratches in the cup that appear to have been made during manufacturing, and a 1mm scratch on the shank end, but otherwise there are no major scratches or dents. The mouthpiece will be wrapped in bubble wrap for shipping. The box is not included. #trombone #basstrombone #trombonemouthpiece #basstrombonemouthpiece #windinstrument