Features1FLEXIBLE SHIFTING: Adopting 5 6 7 speed rear derailleur design to realize more flexible and smoother bike shifting. Suitable for most types of bikes, such as mountain bikes, hybrid bikes, folding bikes and so on. 2WITH CONVERTER: Bike rear derailleur comes with a converter for easy installation and adjustment, suitable for Brompton C line single hole frame. With screws and other accessories for easy installation and fixation. 3STABLE AND PRECISE OPERATING: The rear derailleur is designed to ensure the accuracy and stability of shifting operating. shifting performance ensures your safety and stability while riding. 4 MATERIAL: This bike rear derailleur is made of aluminum alloy and nylon materials, sturdy and reliable, not easy to deform or damage, can be used for a long time. 5NOISE REDUCING PULLEY: 8T nylon and fiber pulley design can effectively reduce the friction noise when the chain and pulley bite together, can be removed and replaced with 10T or 12T pulley.SpecificationItem Type:BikeRearDerailleurMaterial: Aluminum Alloy, NylonApplication: For Brompton C Line Single Hole FramePulley: 8T, pulley made of nylon with fiber, effectively reducing friction noise when the chain and pulley biteFlywheel: Compatible with 11 to 28T flywheelPackage List1 xBikeRearDerailleur2 x M4 Nut2 x M4x16MM Screw2 x M5x18MM Screw1 x M5x6MM Screw1 x Converter1 x Arc Washer