AD 56505756 11" Union Mix Rotary Disc Scrub Brush for Nilfisk Advance Scrubbers. Union is a mix of natural tampico and bassine fibers which creates a soft scrub brush. This natural fiber brush can be used on decorative or polished flooring for very light cleaning and "dusting". Union brushes are also commonly used to apply waxes and polishes to wood and concrete flooring. These brushes have limited life as compared to their synthetic counterparts. Filament is set in an 11" diameter solid heavy duty plastic molded block. Includes 3 mounting drive lugs. Fits Nilfisk Advance scrubbers including Adgressor 3520 (with 35" disc scrub deck), Adgressor BR 950S, Advenger 2400D, Advenger BR 600S, 1700, 2067, Convertamatic 24D-C, X24D-C, 240, HydroRetriever 240, Trac 240, 240HD, 240LX, 240HR, and 4500 These brushes have a 5-1/2" center hole. Many machines require two, or in some cases, 3 or 4 brushes. Please check your machine before ordering. Often listed as 12". Replaces Nilfisk-Advance 56505756, 505756. Our Part Number AD 56505756