Eastwood's 6in Round Hook and Loop Film Backed Sand Paper lasts twice as long as paper backed abrasives and is super durable and tear resistant. Film is constructed of a plastic substrate which is flat so the grains are even across the surface; this creates a more uniform sanding surface. Another advantage of Film is because the backing is plastic you can use it wet or dry. Packaged in conveinient job size 5 packs, available in several grits. Eastwood 6IN Film Backed Sandpaper H&L 400 Grit 5PK