Shimano Cues RD-4020 9-Speed Rear Derailleur SGS Cage Key Features Shadow design features a super low profile and optimized slant angle for light shifting action and improved clearance Wide link design increases rigidity and service life One Fluorine-coated link pin bushing Large 11 tooth pulleys are used for longer life Aluminium bracket body with steel outer and inner plates For double, total capacity 41T, max front difference 16T 9-speed Compatible with LINKGLIDE and HG 11-speed chains Compatible with 36T low sprocket E-bike rated About Shimano CUES CUES range of components for mid-grade riding styles offers simplified compatibility, versatility and durability LINKGLIDE technology is very durable, up to 300% more durable than current Hyperglide drivetrain and maintaining smooth shifting To configure your CUES groupset please use this easy to use chart linked, just fill in the bike type and speeds required and simply pick the components required CLICK HERE