Product description *Suitable for SHIMANO DA9100 DA9150 R8000 R8050 transmission *12/17T super large size guide wheel set system *Saves 45% chain friction resistance compared to 11T guide wheels *Ceramic bearing version saves more than 2.2 watts of average power compared to the original transmission system *Full carbon fiber cage *Full 7075 aluminum alloy CNC cutting lightweight guide wheel and TC4 titanium alloy spindle *Color: Anode red, enamel, blue, gold, green *Ceramic bearing version Ceramic Bead Bearing Version NSK Steel Bearing Version *Weight: 17TH: 55g *The ceramic bearing version is 1.2 grams lighter than the steel bearing version