Flap Disc Abrasive Type Coated Abrasive Material Zirconia Alumina Grade Coarse Backing Plate Material Plastic Connector Size 7/8 in Connector Type X-Lock Flap Disc Type Type 27 Overall Diameter 4 1/2 in Quick Change System X-Lock Series X-LOCK Backing Material Plastic Grit 120 Maximum Operating Speed 13 300 RPM Features Trimmable