Trombone Blow Supporter This improves the sound by reducing resistance when playing, allowing for smoother airflow. Easy to use: Simply roll this product into a tube and insert it into the joint on the bell side. The key is to insert it until it gently hits the end of the tube joined to the rotary valve side. This product can be attached to instruments using standard rotary valves. The shape is designed to fit large-bore tenor trombones and bass trombones using standard rotor valves, such as BACH 42A, B, C, 50A, B, and Edwards. It may be possible to attach it to other manufacturers' instruments, but if the dimensions don't fit, you can easily cut it with scissors and adjust the shape. It cannot be used on tenor trombones or instruments with special valves. Also, we cannot answer inquiries such as "Can this be used on the △△ model from ○○ company?" Please note that the perceived effects may vary from person to person.