A dirty drivetrain causes poor shifting and unnecessary wear to expensive parts. The Chain Gang contains everything needed to quickly and easily clean the chain, freewheel cogs, and chainrings.Park Tools Chain Gang Cleaning System Features: CM-5.2 Chain Scrubber GSC-1 GearClean(R) Brush 8oz bottle of CB-2 Citrus Chain Brite The CG-2.2 works on all derailleur bikes and many 3-speed and coaster brake bikes. Style number CG-2