This product is sold either as a single unit or a case of 10 pads.
These foam/hook pads are meant to be used alongside loop backed discs on the porter-cable and other like drywall disc sanders.
LIGHTNING™ PAPER DRYWALL HOOK & LOOP DISCS
SMOOTH-KUT™ PAPER DRYWALL HOOK & LOOP DISCS
WET-KUT™ CLOTH DRYWALL HOOK & LOOP DISCS
DUAL/SINGLE ANGLED DRYWALL SANDING SPONGES