Features： 1、104mm BCD. 2、Aluminum alloy material for light weight and strong strength. 3、170mm length for crank arm.Compatible with 8 / 9 / 10 / 11 / 12 speed. 4、Chainring with arrow\u0026wide teeth increase chain retention and wear life,reduce friction and noise. 5、Bottom bracket can be used with a bracket shell width of 68/73mm. 6、Suitable for most mountain bikes. Specification： Good replacement for your mountain bikes. Features: 104mm BCD. Aluminum alloy material for light weight and strong strength. 170mm length for crank arm.Compatible with 8 / 9 / 10 / 11 / 12 speed. Chainring with arrow&wide teeth increase chain retention and wear life,reduce friction and noise. Bottom bracket can be used with a bracket shell width of 68/73mm. Suitable for most mountain bikes. Specification: Color: Black / Red (optional) Chainring Teeth: 34T / 36T (optional) Crank Arm: Material: Aluminum alloy Compatible with: 8/9/10/11/12 speed BCD: 104mm Length: 170 mm / 6.7 in Axis outer diameter: 24 mm / 0.9 in Axis length: 118 mm / 4.6 in Weight: approx. 700 g / 24.7 oz (for a pair) Chainring: Chainring Teeth: 34T / 36T Diameter: (34T)144mm / (36T)153mm Material: Aluminum alloy BCD: 104mm Weight: approx. (34T)52g / (36T)55g Bottom Bracket: Material: Aluminum alloy Fits for: 68/73mm width of bracket shell , BC 1.37-24T BCD: 104mm Inner diameter: 24 mm / 0.9 in Weight: approx. 92 g / 3.2 oz Package List: 1* Right Crank Arm 1* Left Crank Arm 4* Chainring Bolt 1* 18mm Crank Screw 1* Chainring 1* Bottom Bracket Package List： 1* Right Crank Arm 1* Left Crank Arm 4* Chainring Bolt 1* 18mm Crank Screw 1* Chainring 1* Bottom Bracket