Description: 【Premium Material】Bicycle Rear Derailleur Hanger is made of aluminum alloy material, solid and firm, very durable, has fine workmanship, and can be used long time. 【Easy to Use】 Rear derailleur hanger extension fit for a wide range bikes style cassette., Increased by 41mm, it can be used when the rear flywheel is changed to 36T, 40T, 42T, 44T, 46T, 50T, 52T, 56T. 【Easy to Install】You can change and install the bike tail hook extension simply, adjusting the tension and expanding the flywheel speed change more smoothly. 【Good Accessories】Adding this product to the bicycle eral dial hook bikes converter, you can easily solve the troubles you encounter. Great accessory for cycling enthusiasts. 【Package Included】1x Hanger Extension Extender, and 1x Screw. With great performance on the rear derailleur extension, also can be an excellent gift for your cycling friends. Specification: Material: Aluminum Alloy Size: 6.3cmx2.3cmx1.2cm/2.48inchx0.91inchx0.47inch Package Includes: 1 Derailleur Hanger Extension 1 Screw(2 Pack) Note: Please allow slightly errors due to manual measurement and different monitors.