Profile Cromo Cassette Driver
• Manufactured at Profile Racing's U.S.A. plant using chromoly. These CNC machined cassette drivers fit all of Profile Racings cassette hubs and accept Profile Racing cogs sizes 12T to 18T.
• Pawls & springs not included. (sold only as a set - 4 springs and 4 pawls). Note: if you are switching from a Profile Racing 9-10-11T cog/driver you will not need the springs & pawls. You will be able to transfer them from one driver to the other.
• It is important to also replace your chain whenever you install a new driver or cog. A worn, stretched chain will cause your driver or cog to wear out much faster."