Nylon Thread Locking (male) screw hub . Roloc® type system Easily screws into holder (sold separately) Rapid Disc Changes Smooth Running Centered Disc Increased Productivity Durable Backing Aggressive Stock Removal Aluminum Oxide Abrasive on Part #'s 7302 & 7303 Ideal for Flat or Contoured Surfaces Woven Fabric imbedded in nylon structure on Part #'s 8002, 8003 General Purpose grinding, deburring, blending and cleaning Deburring: Removal of exit burrs, weld-splatters, die-cast flash and parting lines Part # 8002 is ideal for cleaning: removing paints, corrosion, coatings, gaskets and adhesives Ideal for prolonged edge work For use on ferrous and non-ferrous metals Maximum RPM rating for 2" Diameter: 25,000 rpm Maximum RPM rating for 3" Diameter: 20,000 rpm 