Precision CNC machined.2 dog type.L/H thread - 1.29"x24TWeight:Â 7g7075 Alloy in anodised Black, Blue, Red, Green, Gold or Purple.Larger point of contact with hub for increased securityNote: General Fixed sprocket check: for correct fixed use, the fixed sprocket should NEVER move on the hub when pedal force is applied in both directions.i.e. if the sprocket moves, then something is wrong.Continued use with a fixed sprocket that moves will result in damage to the hub.