Box Four 8 Speed Rear DeraileurThis Box Four rear mech is the base of Prime 9 Technology, which offers an affordable clutch based 1 by 8 speed derailleur that is simple and light. This makes it an ideal candidate for every entry-level bike that traditionally has a 3 by drivetrain that is neither durable nor user friendly. This rear mech is suitable for road and off-road use and gives rider's fast and consistent operation on the most demanding of rides.FAQ:Are Box Prime 9 derailleurs compatible with Shimano "direct mount" hangers? No, Shimano direct mount hangers are proprietary and are not compatible with Box derailleurs.Is the Box Four Prime 9 Derailleur compatible with other 8 speed components? No, traditional 8 speed systems use a Cable Pull that is not compatible with Prime 9.Are Box Prime 9 derailleurs compatible with drop bar (road) shifters? No, Box Prime 9 derailleurs are not currently compatible with drop bar shifters, but we do offer a clamp for our shifters to mount on some 31.8mm drop handle bars.How should I clean my Box Four Prime 9 derailleur? We suggest removing the derailleur from the bike and using a soft bristle brush or rag with soapy water or a mild de-greaser. We do not recommend pressure washing, strong solvents or de-greasers as they could degrade the surface coating.Features: Material: Aluminium, Glass Fibre / Nylon Composite, Steel Limited Slip Clutch Bearing Pulleys Nylon Composite Knuckle Direct Channel Cable Stay Die-Cast Linkages Stamped Inner and Outer Cage Compatible with Standard Derailleur Hangers (Non Direct-Mount)Compatibility: Box Four 8 Speed Shifter Black Box Four 8 Speed 116 Link Chain Natural Box Four 8 Speed 11-42T Cassette Black Box Four 8 speed Wide/Narrow Chainring 104BCD 32T BlackWeight: 328gBuy Box Components from Chain Reaction Cycles, the World's Largest Online Bike Store.