MTB Bike Tail Hooks Derailleur Aluminum Alloy Bicycle Frame Rear Hooks for Mountain Bikes Road Bikes Color Style and Size: Red, 45 x 22 x 12mm. Specifications: The screws supplied with the extension require a 6mm wrench Installation and application: Most tail hooks are compatible, but some tail hooks need to be modified by yourself! Note: This extension is used to lengthen the tail hook. It is mainly used when modifying the enlarged style flywheel. It is more professional. It is recommended to modify it after learning and understanding. Easy installation: Easy removal and installation with a set of screws Scope of application: The bicycle rear rack is suitable for most types of bicycles, which can reduce the maintenance cost of the frame. Excellent quality: The frame tail hook extender is made of durable and compact aluminum alloy, which can extend the service life of the product, aluminum alloy material, strong and durable, high strength, corrosion resistance. Function: This rear derailleur extender helps to evenly increase the speed change of the cassette, allowing you to enjoy riding. Cut-out design: The derailleur adapter has a cut-out design, light and beautiful, with bolts, suitable for rider carrying. If you have it, you don't have to worry about malfunction during riding. EXQUISITE GIFT: The mountain bike derailleur rear bracket is a great accessory for cyclists, an exclusive gift for cyclists, no longer worry about malfunction during riding.