FC 18-421C 18" .035"/180 Mid Grit Scrub Brush for Factory Cat Tomcat 350D, 52, 5100 Scrubbers which require 8-pt scrub brush drivers (6pt Pictrued Above). Our most popular grit scrubbing brush for everyday scrubbing of hard surfaces such as sealed concrete, unsealed concrete, tile, terrazzo, travertine, older epoxy painted flooring and shop floors. Long lasting .035" diameter DuPont Tynex-A or Hahls Nylon is impregnated with medium sized 180 grit silicon carbide granules. Equivalent to Midi-Grit, Scrub-Grit 3. Commonly grey or blue in color. Replaces blue floor pads. 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 FC 2-421C for 6 pt.). We also offer two more aggressive brushes for heavier dirt and debris (use FC 18-421SS, Super-Grit Equivalent or FC 18-421S Tough-Grit Equivalent). 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 18-421C, 52-421C. Our Part Number FC 18-421C