Features: Make of aluminum Alloys, strong and enduring, high strength, hardness, not easy to deformation. Features a square hole designs, enhancing the cranks aesthetic and strength. This crank arm is divides into left and right side, please pays attention to the left and right side when installing. This crankset offers a balance between light weight and durability for mountain biking. Available in 170mm and 172.5mm lengths to suit different cyclists preferences and bike types. Specifications: Materials: Aluminum Alloys Length: 170mm (6.69inch)/172.5mm (6.79inch) BCD: 104/64mm Suitable for: 7/8/9/10/11 speed Package Includes: 1set Mountain Bike Crankset note: Please allow 1-2cm errors due to manual measurement, make surely that you not mind before order. Due to difference between different monitors, the picture may not reflect the actual color.