3M 20907-320 - X-Fine Sanding Sponge, SandBlaster sanding sponges offer up to 3 times longer life and cuts up to 3 times faster than traditional sponges. 3-3/4"" x 2-5/8"" x 1"" thick. Color coded packaging for type of sanding job. 36 and 60 grit sponges