Dirt in your drivetrain is a bummer for all sorts of reasons, but Park Tool's CM-5. 2 Cyclone Chain Scrubber makes it easy to keep your links clean. An internal reservoir holds two ounces of chain cleaner, a magnet keeps small particles from reentering your chain after they've been brushed out, and stiff brushes work out grime without damaging your chain. There's even a small sponge to absorb extra solvent and make sure your chain doesn't hold onto degreaser after it's been cleaned.