Unlike regular sandpaper which is prone to wrinkling and tearing, the flexible, cushioned sponge backing of Infini Model’s Softback Sanding Sponges is designed to follow the contours of your project beautifully, resulting in a finer finish in less time. Using an advanced manufacturing process, Softback Sanding Sponges abrasive grains are adhered to the backing with an electrostatic charge, providing a uniform sanding surface and longer life as compared to typical sandpapers which are uneven, inconsistent and held together with glue. Plus, Softback Sanding Sponges can be used for dry or wet applications for maximum versatility. When your project requires a superior finish, Softback Sanding Sponges are the right tools for the job. Set of six 5-1/2” x 4-1/8” Softback Sanding Sponges includes one each 220, 400, 600, 800, 1000 and 1500 grit. 2-pack refills of each grit available separately. For even more applications and finer finishing options, see our Softback Sanding Sticks, in grits from 220 to 4000.es can be used in both dry and wet sanding applications. Dust and dirt caused by polishing doesn't stick to the sanding sponges easily and they can be washed off. 50% longer lifespan than similar products! Pads are 5-1/2” x 4-3/16” single-sided.