Gator waterproof sanding sheets are designed for applications where wet sanding is required Cut to fit 1/2, 1/3, or 1/4 sheet clamp-on sanders The paper backing is specially treated to maintain it's strength and shape even after being soaked in water for an extended period of time The sharp, fast cutting silicon carbide grain works well on metal surfaces and between coats of paint, primers and sealers For wet sanding primers, base coats, and top coats The premium backing allows the sandpaper to be submerged in water for an extended period of time without any adverse effects on the quality of the sanding sheet For hand or machine sanding Grit Type: Mirror Fine It is a wet and dry sandpaper