Norton Sanding Discs 80 Grit 45-Pack with Free Backup Pad Designed to fit the Porter Cable Model #7800 Drywall Sander. Aluminum oxide abrasive with a velcro backing attaches to the Porter Cable Drywall Sander 7800 via the Norton Backup Pad. Replaces expensive Porter Cable sanding pads at a fraction of the cost. Features: Aluminum oxide abrasive for an ultra smooth finish on your drywall surface Anti-clog coating on disc decreases loading and promotes optimal dust collection when paired with the Porter Cable Sander The rugged hook & loop fastening system assures quick and easy disc change. 80 Grit 9 inches round 45 discs per packFree Norton Backup Pad included - attaches to sander head using existing nut