Top Part for Bb- Trumpet - Ronald Romm (Canadian Brass) signature model - This unique cup design reacts like a flat mouthpiece, but has a deeper shell with more V-shape on the lower half - Internal diameter of the cup: 16.26 mm - Outer diameter: 28.40 mm - Bore # 27 - Silver-plated THIS ITEM IS CURRENTLY NOT AVAILABLE YOU CAN CONFIRM THIS INFORMATION BY CLICKING ON ITEM