FC 28-521P 28" 18SR Poly Cylinder Scrub Brush for Factory Cat / Tomcat 28, 2800C, 29, 3000C, 350C, 30 (MiniMag/Magnum/GTX30) Scrubbers. An economical alternative to the soft Nylon brushes, the poly scrub brushes are great for general duty scrubbing tasks on almost all flooring surfaces. The small .020" diameter poly reaches into cracks and grout lines. These can be used on sealed and unsealed concrete, polished concrete, older painted and epoxy painted flooring, tile and most stone surfaces. Fits Factory Cat and Tomcat 28, 2800C, 2800EX, 29, 3000C, MiniMag 30, Magnum 30, GTX 30 and 350C scrubbers which require two 28" cylindrical scrub brushes (Listed as a 30C Old Style - 30" scrub path with brush 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. Two brushes required per unit. Priced each. Replaces Factory Cat / Tomcat 28-521P