S.E. Shires Bass Trombone Mouthpiece Vintage 1-1/4G This is a Vintage series bass trombone mouthpiece from S.E. Shires. Outer rim diameter: 39.00mm Inner rim diameter: 28.00mm Throat: 7.30mm Although it's a quarter size, it's made slightly larger than the same size from V.B. company. This allows for a deeper breath, and is recommended for those who feel something is lacking. *No box