Park Tool GearClean Brush (GSC-1)

This brush’s curved, toothed-end makes it so much easier to dig grime out from between cassette cogs without shredding my fingers. The handle is comfortable even after scrubbing for a while, and it really gets the deep dirt that builds up on a dirty chain.

The handle is nicely padded and comfortable to grip, even with greasy hands. It really digs into the cassette to get the grime out, though I wish the bristles were just a touch stiffer for really caked-on drivetrains.