Rudolf Meinl RM 2. Mouthpiece for Tuba, Mouthpiece, Mouthpiece for 3/4 B tuba, larger backbore than RM 2, Inner cup diameter: 31.5 mm, Outer cup diameter: 47.0 mm, Cup depth: 38.0 mm, 0.2 mm larger back bore than RM 2, Silver-plated
