3M 99420 Pro-Pak Wetordry Silicon Carbide Sandpaper, 400 Grit, 25-Count3M Pro Pak Tri M ite Wetordry Silicon Carbide Sandpapers use to sand between coats of paint, varnish or other finish. Flexible "A" weight backing for contour sanding wet or dry. Can be used with water to reduce clogging and extend abrasive life. Features silicon carbide, a sharp, synthetic material that cuts fast and smooth. Packages are tri lingual and die cut for convenience. 25 Count Size: 9" x 11" Grit: Super Fine 400 Abrasive Backing Weight: A