PARK TOOL - GSC-3 DRIVETRAIN CLEANING BRUSH
This dual-sided brush is specifically designed for cleaning hard-to-reach areas of the bicycle drivetrain. The long, stiff bristles of the GSC-3 are narrow enough to reach between the gears of tightly-spaced modern cassettes, while the slim contoured end is capable of picking grit and grime out of tight spaces such as derailleur pulley wheels.