GR Compu-Bal trumpet mouthpiece 63 rim BR_CLEAN The specially designed Optimal Pressure

The specially designed Optimal Pressure System fits right into your trumpet and works with your normal mouthpiece top to teach you to use less pressure while actually playing

Feature the GR Classic Blank

Designed and measured to fit one euphonium (bell up and forward)

Indestructible - made from tough Delrin plastic - great for students

OUTER DIMENSIONS

GR Compu-Bal trumpet mouthpiece 63 rim BR_CLEAN The specially designed Optimal PressureQuick Comparison The GR 63 Series cup diameter is somewhat similar to a conventional 10 diameter. Classic Blank is standard. Studio, Symphonic, and FatBoy are available as a special order on some models.