DENIS WICK Euphonium Mouthpiece ULTRA-X SM Model SM4X Specifications (from product list) Cup Inner Diameter: 26.00mm Rim Width: 6.3mm Throat: 7.4mm Backbore: V-Type Shank: Large Shank Finish: Silver Plated Contents: Mouthpiece, Original Box, Inner Bag, Manufacturer's Product List I purchased this new and used it dozens of times, but it didn't suit me, so I'm selling it. There is some overall wear and tear, but there are no major scratches, including on the shank and mouthpiece receiver joint.