3M 99421 Pro-Pak Tri-M-ite Fre-Cut Wetordry Sandpaper, 9"x11", 320 Grit, 25 Count3M Pro Pak 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 Use to sand between coats of varnish, paint or other finish Can be used