Trombone Mouthpiece Courtois (Antoine Courtois) Becke Model, Large Shank, 5L SP Cup Inner Diameter: 25.60mm Rim Width: 7.50mm Bore Size: 7.05mm This mouthpiece was included when I purchased a Courtois trombone. I threw away the box, but it was stored in a bag, so it's in relatively good condition. I can't use it due to a metal allergy, so I only tried it once. It has been cleaned and disinfected. Please understand that there may be minor scratches or dirt as it is a used item. It will be wrapped in cushioning material and shipped in a cardboard box. Description This mouthpiece was supervised by the world-renowned trombone player, Michel Becquet. It features a large cup and bore, and a solid rim. It produces power and a rich, deep sound.