Machined 7075-T6 aluminum Singlespeed cogs. Wide base prevents the cog from digging into freehub bodies and reduces flex. Splines are machined for perfect alignment and fit on all mountain cassette hubs. The shape, width and height of the teeth are CAD designed and optimized for Singlespeed use with 3/32″ chains (1/8″ OK) . The design offers more contact with the chain rollers for better wear resistance of both the cog and the chain. Positive engagement prevents chain slippage and makes for a very quiet drivetrain. 100% made in the USA