The Tektro RX 4.0 Reverse Lever works with caliper or cantilever brakes and include external cable routing. Requires mountain end brake cable.Fits bar I.D. of 19-21mmRequires mountain end brake cableWork with caliper or cantilever brakesItem SpecificationsBrake Lever ActuationShort PullBrake Lever UseLeftBrake Lever UseRightCable HeadMountain