The Bob Reeves Two Piece Trumpet Mouthpieces are designed to offer the player the best possible combination for their particular playing needs through a combination of rim and cup sizes matched for optimal performance. The Reeves Two Piece Mouthpiece number system uses small to large cup diameters ranging from low to high and cup depths ranging from extra shallow (ES) to deep (V). Each of these mouthpieces uses a standard #2 backbore and standard #4 shank. Bob Reeves has been working with brass players, making mouthpieces, and adjusting their instruments since 1964 and continues to study and improve upon the methods and fine products that he has developed.