An aggressive brush for general scrubbing or stripping finishes from hard surfaces. Effectively cleans wide grout lines. All clean grit brushes must be run in a wet environment at all times. We have a 20" nylon brush that can be used on any surface, with any of our 20" walk behind scrubbers, including our Performer 20 hard floor scrubber. The bristles are attached to a plastic block, and are 1-1/2" long, which really help to scrub uneven surfaces, and get into all the nooks and crannies of a hard floor.