Alpha® PVA QC “Quick Change” Back pad available in 4" or 5" The aluminum backer plate is attached to the polishing tool and each of the pads has a snail lock adapter. The adapter simply fits into place and locks on with a twisting motion. To remove the pads simply untwist and remove, then replace with the next grit. This “Quick Change” process saves time, increases productivity and is an Alpha® exclusive. For use on PVA, antiquing brushes, and other snail lock, TWINCUR and other line Pads.