K&G Euphonium 3.5D+, Mouthpiece for Euphonium, Inner diameter of the cup: 26.40 mm, Cup depth: D (Deep), Medium wide rim, Large shank, The new series of Trombone Masters Edition mouthpieces have been developed to achieve more precision, Features the same rim profile, cup and bore as the standard series, but with a redesigned backbore that provides maximum accuracy, The Standard Series is broader in sound quality, while the Master Series has more definition, Silver-plated