Fiber Disc Disc Diameter 5 in Mounting Hole Size 78 in Abrasive Type Coated Abrasive Material Zirconia Alumina Abrasive Grit 36 Abrasive Grade Extra Coarse Disc Backing Material Fiber Backing Weight Y Max RPM 12200 RPM Series 3Z Color Brown Vacuum Hole Design NonVacuum Package Quantity 100.