The Norton 9" hook-and-loop drywall sanding backup pad for Norton A290 paper-backed discs provides extra support, enabling the use of heavier pressure without tearing the disc. This pad mounts to the Porter Cable model 7800 sander (sold separately) with a hook-and-loop mounting system, ensuring quick and easy installation and removal. Back-up pads provide the backing surface for attaching a sanding disc to grinders, orbital sanders, polish sanders, and other grinding machines. The back-up pad composition and design affect results. For example, a firm pad provides a more aggressive cut. A medium back-up pad provides greater flexibility. A slotted hub draws cool air behind the disc to reduce generated heat on the workpiece. Sanding discs attach to the back-up pad in a variety of ways, such as with locking nuts, adhesive, or a hook-and-loop system for quick disc changes that don’t require tools. Norton Abrasives manufactures sanding, grinding, and polishing abrasives. The company, founded in 1885, meets International Organization for Standardization (ISO) standards 9000 and 14001 for quality and environmental management.