Trombone Blow Supporter Inserting this product deep into the joint between the bell and slide reduces resistance when playing, improving the flow of air and enhancing the resonance of the sound. Inspired by the acoustic sleeve included with the BACH La Rosa model, this product was developed after careful consideration of materials and shape, with the cooperation of over ten professional and amateur musicians. Everyone who assisted in the development experienced a noticeable change in sound and playing feel, and gave it high praise. It can be installed on instruments using a general rotary valve. The shape is designed to fit large-bore tenor trombones and bass trombones using general rotary valves, such as BACH 42A, B, C, 50A, B, Getzen, and Edwards. While it may be possible to install it on other manufacturers' instruments, if the dimensions do not fit, you can easily cut it with scissors and adjust it to the appropriate shape for use. It cannot be used on tenor trombones or instruments using special valves. Also, we cannot answer inquiries such as "Can this be used on the △△ model from ○○ company?" There may be cleaning marks on the surface of this product, but this does not affect the quality. Please note that the perceived effects may vary from person to person.