Detail 01
18mm cup diameter
The widest in this series. More lip vibrates, which helps low notes and volume but demands more air.

Independent shopping perspective
A 4N French horn mouthpiece: wide 18mm cup with a narrow rim. Suited to players who want volume and low-register support without a broad rim.

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
The widest in this series. More lip vibrates, which helps low notes and volume but demands more air.
Detail 02
Narrow. Less lip contact means easier slurs and flexibility, but more pressure on a small area.
Detail 03
The largest throat here. Air moves freely, so the horn blows open and loud playing stays clean.
Detail 04
A straight-walled bore section behind the throat, feeding the wide cup and open throat consistently.
Detail 05
N marks the narrow-rim version. The plain 4 has the same 18mm cup with a wider 5mm rim.
Detail 06
Feels warmer and slightly grippier on the lip than silver, and helps if silver irritates your skin.
Final check
Product questions
Straight answers to the questions shoppers most often ask about this product.
Same 18mm cup, throat and backbore. The 4 has a 5mm rim; the 4N narrows it to 3.93mm for more flexibility and less lip contact.
Not the best first choice. Narrow rims are less forgiving over long sessions. A wider rim like the 5 is easier to build endurance on.
Not directly. The wide 18mm cup favors volume and low-end body. The narrow rim aids flexibility, but smaller cups are the usual route upward.
Not meaningfully. The difference is feel and comfort against the lip, plus an option if silver bothers your skin.
Reference
The complete catalog record, organized around the decisions musicians make when comparing gear.