Norton Hook & Sand Hoop and Loop Disc, Paper Backing, Hook and Loop, Aluminum Oxide, 5 Hole Count, 5 inches Diameter, P220 Grit Size (Pack of 25) 5" diameter disc with 8 universal vacuum holes is compatible with 5- and 8-hole random orbit sander Hook-and-loop abrasive discs can be removed and reattached multiple times with no loss of adhesion, which can increase abrasive disc life Aluminum oxide grit is a common choice for general-purpose grinding of wood, metal, fiberglass, and plastic, and is more durable than silicon carbide grit Zinc stearate coating prevents clogs from forming and extends the life of the abrasive A-weight paper backing is the lightest weight and most flexible paper backing option, and provides a more consistent finish than fiber or cloth backings