Detail 01
16mm cup diameter
The narrowest in the BFL range. Easier to control up high, tight for players with fuller lips.

Independent shopping perspective
Gold-plated 5BFL flugelhorn mouthpiece: 16mm medium-deep cup on a standard USA shank. The narrowest cup in the BFL range, aimed at control and endurance.

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 narrowest in the BFL range. Easier to control up high, tight for players with fuller lips.
Detail 02
Keeps the round flugel darkness but responds quicker than the deep FL and F cups in the same line.
Detail 03
Fits horns cut for the American taper. European-shank flugelhorns need the F-series pieces instead.
Detail 04
The widest rim offered here. Spreads pressure over more lip for endurance, at the cost of quick flexibility.
Detail 05
Tighter than the 4.60mm throat on most of the range. Slightly more resistance and back pressure.
Detail 06
Sits warmer and slicker on the lip than silver plate, and it's the usual choice if silver irritates your skin.
Final check
Product questions
Straight answers to the questions shoppers most often ask about this product.
The 5BFL has a 16mm cup, 5.30mm rim and 4.50mm throat. The 4BFL is wider at 16.50mm with a 5.13mm rim and 4.60mm throat.
It fits horns with a standard USA shank receiver. If yours takes a European shank, you need an F-series piece instead.
Mostly feel. Gold sits warmer and slicker against the lip than silver, which matters most if silver plate bothers your skin.
It's a medium-deep cup, so round and dark with quicker response than the deep FL and F cups in the same series.
Reference
The complete catalog record, organized around the decisions musicians make when comparing gear.