MTB Bike Rear Derailleur Link Hanger Extender Frame Tail Hook Extension Cycling Bike Bicycle Flywheel Adapter Aluminum Alloy Fitment: Compatible with flywheel expansion schemes such as mountain bike 40 or 42 or 46 or 50 or 52T. Material: Made of aluminum alloy. And the locking screw is upgraded to aluminum alloy to make the locking torque greater. The surface is anodized, which will not fade after being exposed to wind and rain. CNC hollow design: The large-scale hollow and lightweight design, coupled with muscle-like plump and smooth lines, is the perfect combination of power and beauty. Structural upgrading: Accurate adjustment, abolishing the limit position on the common hanger extender, increase the adjustment range, and easier to adjust in place. Also increase shift speed. Installation tips: Fix the tail hook extender to the previous frame tail hook with screws, and then install the rear derailleur to the tail hook extender. Color: blackandred Size: as shown Quantity: 2pcs Kind tips: 1.As different measuring methods,it will occur 1-3 cm deviation about the items,please ensure that it is okay for you before ordering. 2. Because of different monitors and lamplight, the picture may not reflect the actual color of the item, really thank you for your kind understanding. 3. Only the above package contents, excluding other products.