Wire Wheel Brush, Wire Wheel Brush, Bristle-Type Braided Wire, Brush Dia. 4" Arbor Mounting Hole, Arbor Hole Size 5/8"-11, Shankless Abrasive Shank Size, Wire Dia. Bristle Length: 8.7", Abrasive Material Stainless Steel, Face Width: 3/4", Max. RPM 20,000, for use with portable, straight horizontal forks.