This is a tenor horn (alto horn) mouthpiece by Mercer Barker (M&B). The rim is gold-plated. MB3-H Inner Diameter: 18.50mm Rim: 6.25mm Throat: 5.20mm Similar in size to a Denis Wick 3. It has only been used for testing and has been stored. The current retail price is around 33,000 yen.