Used twice, for a total of one hour. I am selling it because the size doesn't fit me. The following is an excerpt from Net Brass: ↓ The inner rim diameter is slightly smaller than Bach 3. The rim is semi-flat and slightly thicker. The rim shape slopes gently towards the outer edge of the rim. The outer rim diameter feels similar to Bach 3. It has a UV cup shape and is slightly shallower than Bach 3C. The throat is slightly narrower than #28 (3.56mm). The backbore is similar to Warburton 5. This is a brilliant mouthpiece that resonates very well. It produces a large sound even with a little breath, so there's no need to overblow. The sound is slightly bright, and the design makes it particularly easy to hit high notes. With a larger rim, a shallow cup, a narrow throat, and a backbore, it's designed to handle all genres with lip control, from low to high notes. Thank you very much.