FC 32-521SG 32" 18 Single Row .018"/500 Soft Grit Light Abrasive Cylinder Scrub Brush for Factory Cat Tomcat 34 (3400, Magnum 34, GTX 34) 35, 35SS, 38, 40, 40HD and 350 Scrubbers with Serial Numbers Below 50000 which require two 32" cylinder scrub brushes with older slotted drive hubs. Our softest non-abrasive cylindrical scrubbing brush for light duty scrubbing jobs on polished, epoxy painted or other sensitive flooring surfaces. Long lasting, .018" DuPont Tynex-A or Halhs Nylon filament impregnated with our lightest 500 grit silicon carbide granules. Lighter and softer than Light Grit. Usually grey or light green in color. Fits Factory Cat and Tomcat 34, 3400, Magnum 34, GTX 34, 35, 35SS, 38, 40, 40HD and 350C scrubbers which require two 32" cylindrical scrub brushes (Listed as a 34" - 34" scrub path with brush overlap. 350C listed as 32" scrub path). 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. For newer "star" style hub brushes, use 325-521SG. Two brushes required per unit. Priced each. Not offered by Factory Cat Tomcat. Our Part Number 32-521SG