Quick Change Disc Abrasive Type Non-Woven Disc Attachment System TR Roll-On/Off Disc Attachment Type Type 3 Disc Diameter 4 In. Abrasive Grit 50 Abrasive Grade Coarse Abrasive Material Aluminum Oxide Disc Backing Material Paper Max RPM 15 000 Series Vortex Rapid Prep Backing Weight B Color Brown