Function introduction: It is suitable for adjusting the tightness between the high-pitched tenor sax leather pad and the key cover to prevent the air cushion from being tight and leaking. Different sizes are suitable for different key covers. Choose the appropriate correction tool according to the key cover Product: Wind Music Repair Parts - L-shaped Leveling Right Angle Key Cover Correction Tool Scope of application: wind instrument maintenance Material: tool steel colour: silver Package Contents: 4 x corrective tools Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.