YAMAHA 47 Trombone (Euphonium) Mouthpiece (Large Shank) Rim Inner Diameter: 24.98mm Throat Diameter: 5.85mm Features: With a slightly smaller inner rim diameter than the 48, it offers excellent durability and can be used in a wide range of settings, from concert bands to orchestras, producing a rich volume of sound. Will be shipped via Yamato Compact. Thank you.