Park Tool Gear Clean Brush
Park's Gear Clean Brush has a handle on one end with a curved, serrated edge perfect for cleaning between cassette cogs. The other end's tough nylon bristles are ideal for cleaning the derailleurs, chain and other drivetrain parts to keep them clean and prevent premature wear. It also works great on brakes and other components that collect dirt and grime. The GearClean easily fits in a toolbox or pack.
WARNING: Cancer and Reproductive Harm