Surfprep 5 in. backup pads are an essential part of you sander setup. Before purchasing your new SurfPrep 5 in. backup pads consider the type of the 5 in. sander you own and what abrasives you are interested in using for your sanding project. Hook & Loop Backup Pads: made with smaller ‘hooks’ which are excellent for the ‘quick release’ of SurfPrep Foam abrasives. J-Hook Backup Pads: have a longer hook design that works well with pad savers, interface pads, film, paper, & non-woven discs/pads. PSA Backup Pads: meant to be used with ‘Pressure Sensitive Adhesive (sticky) backed abrasives for flat sanding.