A dirty drivetrain causes poor shifting and unnecessary wear to expensive parts the park tools chain gang contains everything you need to quickly and easily clean the chain freewheel cogs and chainrings the chain gang works on all derailleur bikes and many 3 speed and coaster brake bikes park tools cg22 chain gang cleaning system features prolong drive train life with this excellent kit contains a cyclone chain cleaner gearclean brush and 8 oz of cb2 citrus chainbrite cleaning fluid