SandBlaster sanding sponges offer up to 3 times longer life and cuts up to 3 times faster than traditional sponges. Color coded packaging for type of sanding job. 36 and 60 grit sponges comprised of aluminum oxide mineral. 80 thru 320 grit sponges made of aluminum oxide abrasive on 4 sides of urethane foam sponge for sanding contoured and hard-to-reach surfaces. Rinse clean and use again. For applications ranging from paint removal to final finish sanding.