Features： 1、High Strength Aluminum Alloy: Our bike crankset is made of aluminum alloy, with light weight, stylish appearance, and strong compatibility. 2、Accurate Processing: Multi stripe fixing method is adopted to ensure the ultimate retention of the chain, prolong the working life, and reduce friction and noise. 3、 Fit: With 104mm BCD, 170mm crank arm, 34T narrow wide chainring and 32‑34T guard disc, the crank set will fit for your mountain bike. 4、Bottom Bracket: BC1.37in X24T hollow and integrated bottom bracket is suitable for most mountain bike in the market. 68‑73mm bottom bracket width and 24mm aperture can be fine. The weight is about 104g. 5、Wide Compatibility: Our bike crank arm set is compatible with 8 9 10 11 speed road bike and mountain bike. Set includes a hollow crank lit, narrow wide chainring, guard disc, and bottom bracket. Specification： Item Type: Bike Crankset Material: Aluminum Alloy Weight: Approx. 1010g/35.63oz Crank Arm Length: 170mm/6.69in BCD:104mm/4.09in Bottom Bracket Aperture: 24mm/0.94in Bottom Bracket Width: 68-73mm/2.68-2.87in Compatibility: For 8 9 10 11 speed Package List： 2 x Crank Arm 1 x Bottom Bracket  10 x Screw   8 x Nut   2 x Dust Cover   1 x Chainring 1 x Guard Disc