※ There is a distortion at the tip of the shank. This is a Willie's BOND 007 bass trombone mouthpiece. It is the signature model of Mr. Zachary Bond, former bass trombone player of the Malaysian Philharmonic Orchestra. Willie's Bond mouthpieces currently have several rim size variations, but at the time of purchase, this was the only size available. It was made to fit Mr. Bond's instrument, a Tine Universal model, but it should also work well with Edwards and S.E. Shires trombones. Rim inner diameter: 28.1mm Throat diameter: 7.9mm As mentioned above, the tip of the shank is distorted. Although I was able to insert it into my instrument without any looseness, if you intend to use it for playing, it would be best to have it repaired or to use it solely for buzzing practice. There are almost no scratches on the rim or cup.