Detail 01
16.50 mm cup diameter
Medium size in this range. Smaller than the 3 at 16.75 mm, larger than the 5 at 16 mm.

Independent shopping perspective
A gold-plated 4X trumpet mouthpiece: 16.50 mm cup, extra-wide 5.75 mm cushion rim, V-type backbore. Built for jazz players wanting comfort and upper-register reach.

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
Medium size in this range. Smaller than the 3 at 16.75 mm, larger than the 5 at 16 mm.
Detail 02
Wide and rounded. Spreads pressure over more lip area, which helps endurance but reduces flexibility.
Detail 03
Compared with the barrel backbore on the 4 and 4C, it favours projection and easier high notes.
Detail 04
Standard for most of this line. Controls airflow resistance and how the sound holds together when pushed.
Detail 05
Feels slightly slicker and warmer on the lip than silver. Also an option if silver irritates your skin.
Final check
Product questions
Straight answers to the questions shoppers most often ask about this product.
The 4X has a wider 5.75 mm cushion rim and a V-type backbore. The 4 has a 5.18 mm rim and barrel backbore, with a stabler pitch centre.
It is aimed at jazz work. For symphonic playing the larger 1, 1X or 1C cup diameters in this line suit better.
A wider rim spreads pressure across more lip, which typically helps on long sets. The trade-off is less flexibility than a narrow rim.
The difference players report is mostly in feel — slicker and warmer on the lip. Cup, rim and backbore drive the sound.
Reference
The complete catalog record, organized around the decisions musicians make when comparing gear.