1.Premium Material: Made of premium aluminum alloy, the bike crank arm set is light in weight, with trendy appearance, and compatible with 8 speed and 9 speed. 2.High Toughness: The bike crank arm set has a muscle line design, higher strength and is more stable for you to step on, therefore it can be used for a long time. 3.Shock Resistant: Made of aluminum alloy and anodizing surface, which can protect its main body, the bike crank arm set is sturdy and shock resistant. 4.CNC Machining: The aluminum alloy crank set adopts CNC accuracy machining, which makes it has high toughness, is suitable for some difficult operation movement, such as mountaineering and off road, with even force. 5.Reduce Noise: The crank arm set for single disk crank can ensure the maintenance of the chain, making its service life longer, and can reduce friction and noise. Item Type: Bike Crankset Material: Aluminum Alloy Weight: Approx. 1188g/2.62lb Color: Black Support Speed: 8, 9 Speed Crank Length: Approx. 170mm/6.69in Axle Length: Approx. 115mm/4.53in Compatible: For SRAM System 1 x Bike Center Shaft 2 x Bike Crankset Accessory 2 x Installation Tool