Gator Grit 3" x 5" 100/60 Grit Fine/Medium Jumbo Sanding Sponge. These 100/60 grit sanding sponges are designed to be used on wood, metal, drywall, fiberglass and painted surfaces. The sponges work best for sanding irregular shapes and contours. You can rinse and reuse the sponges giving them a longer life.