A dirty drivetrain causes poor shifting and unnecessary wear to expensive parts the park tool chain gang cleaning system contains everything needed to quickly and easily clean the chain freewheel cogs and chainrings park tool 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 everything you need to keep the drivetrain system clean and runni