AD 56505205 20" .018"/500 Light Grit Scrub Brush for Nilfisk Advance ConvertaMAX 20, BA 550, BA 5321/D Walk Behind Scrubbers. Our lightest grit brush in this series. Light duty grade grit (.018"/500 grit) grey or light green Tynex-A or Hahls nylon with super small 500 grit silicon carbide granules for light duty scrubbing on sealed concrete, tile, terrazzo, ceramic tile, urethane or epoxy coated flooring, or newer sealed flooring with light to moderate dirt and debris. Commonly called Light Green Grit, Dyna-Grit, Mal-Grit Lite, AgLite Grit, or AgLite Grit 500. Replaces red, white or light green floor pads. If a grit brush is not desired on smooth or polished flooring, use the AD 56325505 soft poly brush. 19" diameter block with clutch plate. Fits Advance ConvertaMAX 20, Nilfisk BA 550 walk behind floor scrubbers. One brush required per unit. Sold each. Replaces Nilfisk Advance 56505205. Our Part Number AD 56505205