This is a MAGNUM 5 mouthpiece for a narrow-bore trombone by Jerome Callet. Jerome Callet trombone mouthpieces are very rare. Although it is new and unused, it is a vintage item that is no longer available new, so there may be some slight cloudiness. Please check the photos for details. 【Product Description】 Manufacturer: JEROME CALLET Model Number: MAGNUM 5 Inner Rim Diameter: Approximately 26.2mm Cup Depth: Slightly shallow Shank: Narrow bore Rim: The width is slightly thick, with a slight edge on the outside and a slight roundness on the inside.