Arm Material: aluminum Arm Length: 165mm, 170mm, 175mm Chainring Sizes: 30T, 32T, 34T BB Type: [threaded] 68mm, press-fit Q Factor: 181mm Built for casual and training all-mountain, enduro, and downhill riding, the Shimano SLX FC-M7130 1x Crank Arms deliver a smooth ride on even the roughest terrains. Its lightweight, stiff aluminum build makes for a fun ride on the trails without sacrificing power transfer or efficiency.