Tuba Mouthpiece PT-88 GP I'm selling this because it doesn't suit me. There are some scratches on the shank, but otherwise, the plating is still intact. Gold plating has become quite expensive, so I think this is a good deal. The following is from the Japan Tuba Center HP: Cup Characteristics: Diameter 33.5mm Large, deep hemispherical shape with a very rounded bottom. Rim Characteristics: Width 7.0mm Rounded inner and outer rims. Throat Bore: Diameter 8.1mm The PT88 model was originally designed for the low register. However, it was found to be suitable for medium-large and large-bore CC tubas as well. It works well with any CC or BB♭ tuba, producing a strong sound with good volume. Recommended for advanced players.