Thank you for viewing. This is an introduction to brass instrument repair tools. New, unused mouthpiece mandrel This is a tool for correcting deformation of the shank of a brass mouthpiece. Made of stainless steel. The part that touches the shank is polished (mirror finish). Compatible with almost all brass mouthpieces for Tp. Hr. Tb. Euph. Tuba. You can check the details of how to use it on YouTube, etc. Search for # Mouthpiece Shank Repair, etc. ● Please confirm receipt after the product arrives. # Mouthpiece Mandrel # Mouthpiece Dent Repair # Mouthpiece Shank # Brass Mouthpiece # Brass Instrument # Brass Instrument Repair # Instrument Repair # Repair Tool # Repair Tool # Trumpet # Cornet # Horn # Trombone # Euphonium # Tuba # Yamaha # DIY