The Robert Tucci RT-7C  is truly a large euphonium mouthpiece which allows great volume and depth of tone.  The RT-7C is ideal for strong players who often perform in large ensembles.

Specifications:
Cup Diameter:  26mm/1.02in, large, wide, and deep configuration
Rim Width:  6.75mm/0.27in, well defined inner edge
Throat/Bore:  7.5mm/0.3in, open backbore