Yamaha GP Mouthpiece Flugelhorn 14F4, Mouthpiece For Flugelhorn 14F4 GP, Heavy, Gold-plated rim and internal bore, Inner diameter: 16.76 mm, Semi-flat contour, Standard thickness, Standard cup depth, Throat: 4.3 mm, Standard backbore, Relatively large rim diameter ideal match for V-cup, A good choice for demanding studio recordings