FC 25-521C 25" 18 Single Row .035"/180 Mid Grit Cylindrical Scrub Brush for 27" Factory Cat / Tomcat Scrubbers. A middle grit scrub brush for general duty scrubbing tasks. Narrow .035" diamater Tynex-A or Hahls Nylon filament impregnated with 180 grit silicon carbide granules for reaching small cracks and into grout lines. Equivalent to Midi-Grit. Fits Factory Cat and Tomcat 26, Magnum 27, GTX 27, 2600C, and 290C scrubbers which require two 25" cylindrical scrub brushes (Listed as a 27 Inch - 27" scrub path with brush overlap. 290C listed as 29" scrub path with overlap). These are the OLD style scrub brushes with the slotted drive system (newer style is a "star" drive with six notches). These are for units with serial numbers BELOW 50000. Please check your unit before ordering. We can also make these in a lighter .022"/120 grit (use 25-521PS, Light Grit Equivalent). Two brushes required per unit. Priced each. Replaces Factory Cat / Tomcat 25-521C. Our Part Number FC 25521C