Description: 360 degree rotation design makes it more convenient for tail hook alignment. Premium aluminium alloy material makes it lightweight while ensuring high strength. Precise thread design helps easily screw the rotating rod into the tail hook for precise lock. Our corrector can help correct the derailleur hanger and solve the problems of inconsistent shifting and drivetrain noise. Made of high quality aluminium alloy material, it is durable. The length of the product is 43cm. Position the O-ring to move the measuring ring to contact the rim, and then move the O-ring to align with the sliding bracket to position it. It is suitable for bike tail hook alignment. Press the sliding bracket to lock the sliding bracket, you can adjust the distance between the measuring rod and the wheel hub, and can measure the deviation between the tail hook and the wheel rim. Item Name: Tail Hook Corrector Material: Aluminum Alloy Features: Precise Thread, Anti-rust, High Strength Size Details: Length: 43cm/16.93" (Approx.) Notes: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 1 x Tail Hook Corrector