Paul Components Melvin Chain Tensioner. Converts frames for single speed use. Long enough for a Dingle-setup, (2 rings, one cog) 20T maxDo not use with a coaster brake or fixed gearIncludes Paul"s own Sealed Bearing PulleysItem SpecificationsColorBlackChain Compatibility3/32",9-Speed,Shim/SRAM 10,Campagnolo 10