Description:Stamped cogs are inexpensive, but tend to take a bite out of your freehub. Wide profile cogs are great, but tend to take a bite out of your wallet. Our Casettte Cog Carrier (CCC) is Shimano-splined, and sandwiches a spline-less cog. This gives you a wide profile that wont damage your freehub, and inexpensive replacement cogs. But wait, are you sitting down? The cogs themselves have a 6-bolt hole pattern, just like disc rotors, so you can attach them to hubs with disc rotor mounts for fixed-gear use.Tech Details:Alloy carrier with steel cogs6-bolt compatible (see instructions for safety warnings)