AD 56505921 18" .070"/46 Grit Super Abrasive Scrub Brush for Nilfisk Advance Floor Scrubbers and Floor Buffers. Commonly listed as a 20" brush. Our most aggressive brush. Thick .070" diameter DuPont Tynex-A or Hahls Nylon filament is impregnated with large abrasive 46 grit silicon carbide granules. These heavier grit brushes can be used on older shop flooring with heavy packed debris, older sealed concrete, and unsealed concrete. The .065"/46 Heavy Grit brushes can also be used for stripping of tile, terrazzo, quarry tile, and other similar hard surfaces. Equivalent to Magna-Grit, .065"/46 Heavy Grit Plus. Replaces black and high productivity floor pads. Not for use on newly painted flooring. Tynex-A or Hahls filaments outlast standard poly and Nylon filaments. We also offer a lighter .050"/80 Nylo grit scrub brush (AD 56505922), or an even lighter mid grit .035"/180 grit scrub brush (AD 56505928). Includes standard universal NP92 (gold cap - AD 56163431) clutch plate. Some other models require a NP47 (silver cap - AD 56163430) clutch plate (if an NP47 clutch plate is needed, please order AD 56505058). Please check your existing brush set up before ordering (if unsure about clutch plate, please reference extra clutch plate in the special instructions box at checkout and we will include both). Most models manufactrued after 1997 were equipped with the newer Gold Cap NP92 clutch plates. Fits Nilfisk-Advance floor machines including Pacesetter 20, 20HD, 20SD, 200, 200HD, Euroclean ECFM 20, Select Line 20, 20TS, Matador 20, SD 20, Spin 20, Convertamatic 20B, 200B, 200LX, 200BD, Shadow 20, SD 5120, Nilfisk BA 500, Hydro-Retriever 200HD, and others. Most machines require one brush. Priced Each. Replaces Nilfisk-Advance 56505921. Our Part Number AD 56505921