Inner Diameter: .640 measured .04 inches into the cup.
Outer Diameter: 1.094
Cup Depth: This mouthpiece has a S (Shallow) cup, which is similar to a Schilke or Yamaha 14A4A, Warburton SV, Reeves S, Bach 3D, or GR S cup. It is an excellent mouthpiece for commercial lead and also for pit and pops. The Wedge rim produces a much better lower register than a comparable mouthpiece of this cup depth, so the low range sounds more like a Bach 3C then it does like a lead mouthpiece. This is also a mouthpiece for Piccolo trumpet if one prefers a shallow cup. Backbore: This top is best used on an S (Small) backbore which can be purchased here.