This 15" poly brush is designed for the . To scrub a 30" path with this machine, you require two brushes, so be sure to pick up two if you need to. Poly brushes are great to scrub uneven floors like concrete, grout, and tile, or textured surfaces. For smooth floors, a may be recommended. The pad driver also allows you to attach stripping and polishing pads in addition to the scrubbing pads. For other sizes of brushes, look at the selection of to find the right size and option for your floor scrubber.