【Mountain Bike Crank Arm】Hollow Integrated, 104 BCD, Crank Arm length 170mm, Crank related holes distance 74m, weight: 670g, Crank screw caliber: 15mm, Compatible with Single/Double/Triple chainring. 【High-strength aluminum alloy】High strength, fine workmanship, improve strength and rigidity. The shaft is made from chrome molybdenum steel, enhancing crank stability and hollow shaft construction. 【Professional Design】Ergonomic shape utilizes the stampede acting efficiently to create more stampede traction. It can help you make your riding easier and more comfortable. 【Package Includes】1 Left Cranks,1 Right Cranks, 4 pairs of bolts, 1 Wrench, 1 Crank Arm Dust Cap. 【Guarantee】We guarantee them all with a 100% product guarantee and promise to offer you the best customer service, if you have any question please kindly feel free to contact us.