FC 225-821N 22" 18 Single Row Soft Nylon Cylinder Scrub Brush for Factory Cat / Tomcat 24 (MiniMag 24, Magnum 24, GTX24) Scrubbers with New Drive Systems. Soft .014" diameter Nylon filament for light duty scrubbing of polished concrete, marble, newer epoxy painted flooring or any other senstive flooring. Equivalent to Nylon, Nylex. Listed as a 24C New Style - 24" scrub path with brush overlap. These have newer splined hub with 6 notched hubs. For models with serial numbers ABOVE 50000. For older models with serial numbers BELOW 50000 with the slotted type drive hubs, use FC 22-521N. Commonly white or black in color. 2 brushes required. Priced Each. Replaces Factory Cat / Tomcat 225-821N. Our Part Number FC 225-821N