Kogel`s extra large Kolossos pulley system gets the aero treatment for top performance on Road, Triathlons and Time TrialsFully built in CNC machined aluminum with an internal spine for maximum stiffnessReduces wind resistance while also maintaining shift accuracyBuilt with Kogel`s ceramoic bearings and road sealsAvailable for Sram Red AXS and Shimano 11 and 12 speed Ultegra and Dura Ace Di2 SeriesShimano 12/19TRaw SilverUPC/EAN/GTIN: 735201961217