Treated fiber sponge, 3/8″ thick x 6″ x 9-1/2″. Very effective mechanical cleaning and fine sanding action. Use with liquid detergents to clean all metal & painted surfaces. Use dry to remove burrs from metal edges, finish sand fine wood & plastic items. Use dry or with acid etch to remove corrosion residue from aluminum surfaces and remove rust from steel surfaces. Excellent for scuff sanding new aluminum surfaces, epoxy primer and two part urethane finishes to provide tooth adhesion. Recommended as a cleanup after paint stripping to remove usual stubborn spots around rivet heads, seams, etc.