Thank you for viewing. This is the BLAKUL Insert Tuba/Hr/Tb. It is made of copper. I am selling it because it didn't quite suit me. It can be used for the rotary valves of tubas, horns, and trombones, and it brings about a change in tone. I used it only for testing, so there are no noticeable scratches or stains. The following is a quote from the website: BLAKUL Insert Tuba/Hr/Tb Copper New price: 7,700 yen ■ How to use 1. Remove the rotary cap 2. Insert the insert 3. Close the cap Complete Copper materials, when used in increasing amounts in instruments, can make the sound unclear, but this product is designed not to sound muffled even when installed. Fine hand hammering moderately tempers the metal, improving the slowness of copper's response. There is a change that increases the luster and density of the sound, and since the change is not as significant as with silver, it is excellent because it can be used without any sense of discomfort. It is most effective when used by attaching it to the rotary valve furthest from the mouthpiece. Even just reversing the front and back can significantly change the impression, affecting the sound's response speed, so you can use it differently depending on the overall balance of the instrument and the scene in which you use it. ■ Although it is made as an item for tubas, it can also be used for horns and trombones. Please feel free to comment if you have any questions or if you would like to purchase. #tuba #tuba #trombone #horn #wind instrument #brass instrument