​Chainring: snail single speed narrow wide teeth chainring, 30T/32T/34/36/38T/40/42T/44T/46T/48T/50T/52T, round/oval chainring,thickness is 4mm (1.9mm narrow, 3.7mm wide) Chainring : snail single speed narrow wide teeth chainring, 30T/32T/34/36/38T/40/42T, round/oval chainring,thickness is 4mm (1.9mm narrow, 3.7mm wide) Bottom Bracket : Size is 41*24*24 mm can fit bike bottom 68-73mm,ideal for Shimano, FSA compatible. Giant ATX770 ATX770-D XTC750 and so on Material : Crank and chainring made of aluminum alloy, light weight, high axial strength and compatibility ​Note:These crank and chainring are only suitable for single speed. Suitable for most mountain bikes ,Compatible With Shimano Sram FSA Introduction:(IXF) Crank Arm length: 170mm Color:Black/Red/Blue/Gold/Green/Purple Material: AL6061 aluminum alloy Compatible: Single/Double/Triple chainrings; for 7/8/9/10/11/12S chains Bolt Center Diameter: 104mm BCD Weight: about 637g (right & left) Advantages: light weight,stylish appearance,very cool,high strength axle,strong compatibility Chainring description: Brand: Snail Type: Single speed Color: Black,Red Material: Aluminum alloy 7075-T6 Bolt Center Diameter: 104mm BCD Teeth:30/32/34/36/38/40/42/44/46/48/50/52T (Round/Oval,optional) Thickness: 4mm (1.9mm Narrow, 3.7mm Wide) Compatible with: 7/8/9/10/11/speed chains (for Shimano/SRAM/FSA crank)