FC 18-421PS 18" .022"/120 Light Grit Scrub Brush for Factory Cat Tomcat 350D, 52, 5100 Scrubbers which require 8 point brush drivers. Long lasting .022" diameter DuPont Tynex-A Nylon is impregnated with medium sized 120 grit silicon carbide granules. Equivalent to Light Grit, Scrub-Grit 2. Commonly grey or red in color. Replaces red floor pads. Our most popular light grit scrubbing brush for everyday scrubbing of hard surfaces such as sealed concrete, unsealed concrete, marble, vinyl tile, quarry tile, rubber flooring, terrazzo, travertine, older epoxy painted flooring and shop floors. The smaller .022" diameter is great for cleaning grout lines. 17" diameter plastic block (18" scrub path) with an 8-point clutch plate (Please check your model for the proper number of points. We offer a 6 point and 8 point clutch plate. Use 2-421PS for 6pt.). We also offer a slightly more aggressive brush for heavier dirt and debris (use FC 18-421C, Midi-Grit Equivalent) or a slightly lighter grit for less aggressive scrubbing (use Our Part Number FC 18-421X Dyna-Grit 500 grit). Fits Factory Cat and Tomcat 350D (Disc Model), 52 and Tomcat 5100 floor scrubbers. Two brushes are required for model 350D, three brushes are required for models 52 and 5100. Priced Each. Replaces Factory Cat Tomcat 18-421PS, 52-421PS. Our Part Number FC 18-421PS