This is a trumpet mouthpiece. ■Manufacturer: Kanstul ■Model: B6B ■Finish: Silver-plated ■Outer box: None ■Condition: Good condition with no noticeable scratches or dents. This is a copy of the current Bach 6B model. It has a screw size compatible with Warburton. I believe it is a very valuable product, along with the advantage of being able to combine backbores as you like. As it is no longer sold, its rarity will only increase in the future. How about acquiring it while you can!