The Johnson Abrasives 9" Foam Backup Pad enables use of standard 9” Hook and Loop Abrasive Discs with the Power Drywall Sander and 9” disc sanders. Using Hook and Loop Abrasive Discs saves money in the long run. Not only is it more economical, but it is more effective than using the stock pads with glued abrasive. Each backup pad lasts through multiple 9” sanding discs rather than having to replace the foam bac-up pad after every Sanding Disc use. Swapping out sanding disc is a breeze with the hook and loop backing. Designed for use hook & loop sanding discs with power drywall sanders. Using the hook & loop system is more economical and effective than using the stock pads with glued abrasive. Use several sheets of sanding discs without having to replace the foam back-up pad each time. The foam pad easily attaches to sander with the stock nut.