Cup Diameter: 32.00 mm, Shallow, bowl-shaped
Rim: 8.50 mm, Semi-cushion with rounded inner edge
Bore: 7.80 mm
Resistance: Moderately strong
Shank: Large

The RT-65 utilizes a cup which is similar to that of the RT-64. The rim is semi-cushioned with a rounded inner edge. Throat and shank bores are calibrated for a dark tonal quality, strong core and excellent low register response. Due to the weight of the rim and body mass of the shell relative to cup volume, this is essentially a heavy-shell mouthpiece. Also works well as an Eb tuba solo or brass chamber music mouthpiece.