Compatible with Most Trumpet - The surface is polished,10.9 mm cup diameter,Compatible with most standard trumpets, such as Yamaha, Bach, Conn, King, etc., Exquisite craft - After 28 production processes and 9 inspection steps, after polishing with precision machine tools, Easy to wipe and keep them clean., Trumpet Mouthpiece Choice - 7C is suitable for beginners or children with small lips, 5C is suitable after some exercises, then 3C is suitable for the professional players. There are 3 packs for most trumpet players choosing., High Quality - Made of Brass ,thick silver plated and does not mix with other materials to ensure the best performance of every mouthpiece,more durable., Trumpet mouthpiece is suitable for students,beginners, professional players,gifts