Signature model supervised by Hidesho Arai. ■Features: The NASOTA 565 has evolved into a mouthpiece that is even easier to play and sounds better for any euphonium player. It uses the rim of the MUSE L5 (equivalent to V.Bach 5GS) and is built on the blank of the BB series for British brass. Inner rim diameter: 25.65mm, throat diameter: 7.22mm Please understand that this is a used item before purchasing.