PFERD 82166 Wire Wheel Brush, Knotted, Diameter: 4 Inch, Face Width: 3/8 Inch, Wire Size: 0.02 Inch, Trim Length: 3/4 Inch, No. of Knots: 22, Arbor Size: 5/8-11 UNC, Max. RPM: 20000, Mounting: Threaded, Filament Material: Carbon Steel