Detail 01
1.010-inch cup diameter
More lip sits inside the cup, which adds volume and low-end body but makes the top of the range work harder.

Independent shopping perspective
A large-shank trombone mouthpiece with a 1.010-inch bowl cup and open J throat. Built for large-bore tenor and orchestral playing, in gold plate.

Strong match
Consider the trade-offs
What matters in use
Catalog numbers tell only part of the story. These are the details most likely to change how this product feels, sounds, or fits into a setup.
Detail 01
More lip sits inside the cup, which adds volume and low-end body but makes the top of the range work harder.
Detail 02
An open throat. Air moves freely and the low register opens up, but you have to supply the air to fill it.
Detail 03
The rounded profile puts weight in the low mids. Sound comes out thick and round rather than edgy.
Detail 04
Seats in large-bore tenor and bass trombone receivers only. Check what your slide takes before ordering.
Detail 05
This is a standard rim, not the wider semi-flat number 4 used on the 51C4, so expect slightly less cushion.
Detail 06
Feels slicker on the lip than silver. It changes grip and comfort, not the cup, throat, or backbore dimensions.
Final check
Product questions
Straight answers to the questions shoppers most often ask about this product.
It is a large shank piece, so it seats in large-bore tenor and bass trombone receivers. Medium and small shank horns take a different taper and will not accept it.
The 52 is slightly wider at 1.015 inches and produces a slightly broader sound. The 51 stays a touch more focused at 1.010 inches.
It is aimed at large-bore tenor and orchestral playing. For bass trombone, the 57, 58, 59 and 60 are the sizes built for that register.
The 51D is 1.005 inches with a very large, deep D cup — fuller and darker, and popular for euphonium and strong players. The 51's bowl cup is more even.
Reference
The complete catalog record, organized around the decisions musicians make when comparing gear.