FC 325-821S 32" 18 Single Row .050"/80 Grit Heavy Abrasive Cylinder Scrub Brush for Factory Cat / Tomcat Magnum 34, GTX 34 Scrubbers with the New Style Splined Drive Hubs. Our most aggressive brush in this series. Durable and long lasting .050" diameter DuPont Tynex-A Nylon impregnated with 80 grit silicon carbide granules. Perfect for heavy duty scrubbing and stripping jobs on unsealed concrete, tile and othert hard surfaces with heavy debris. (Listed as a 34C New Style - 34" 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 32-521S. May fit models that have been converted to new splined brush drives which include 34, 3400C, 35, 35SS, 38, 40, 40HD, and 350 (32" Cyl. Models). Please check your model and brush drive type before ordering. Commonly black in color. Equivalent to Tough-Grit, Nylo-Grit, Black Grit and Mal-Grit. 2 brushes required. Priced Each. Replaces Factory Cat / Tomcat 325-821S