Material: Full carbon fiber frame + Ceramic Bearings + 7075 Aluminum Alloy Guide Wheel ( CNC )17T Gears: 10 and 11 speed Weight: 70g For bike type: Road bike and folding bike above 20 #34; Compatible: For SRAM RED 10S/11S,RIVAL 10S/11S,FORCE 10S/11S SIZE:upper 17T+ Lower 17T Color: Black Features: Lightweight:Carbon fiber derailleur puuleys ultralight for 0.13 lbs Reduce Friction: Save 60% frictional resistance than 11T Smooth: Ceramic Bearings make it smooth and save more than 2.4 watt Durable: Full carbon fiber frame + Ceramic Bearings + 7075 Aluminum Alloy Guide Wheel ( CNC ) Suitable for SRAM RED 10S,RIVAL 10S/11S,FORCE 10S/11S guide wheel group