The newly designed crank arms offer an optimized balance between lightweight and efficiency. The crank, formed with hollow aluminum technology, is anodized with a beautiful silky black finish, giving it a luxurious look.Compatible with 11-speedChainring gear combination (not included): 50-34T, 52-36T, 53-39TRecommended chain (not included): CN-HG701-11, CN-HG601-11, CN-LG500Recommended Bottom Bracket (not included): SM-BBR60 (threaded)/SM-BB72-41B (press-fit)