3M(TM) SandBlaster(TM) Bare Surfaces Dual Angle Sanding Sponge, 180-grit, 9562, 4.5in by 2.5in by 1in, Open Stock, One. The 3M(TM) SandBlaster(TM) Bare Surfaces Dual Angle Sponge is is ideal for sanding bare surfaces, such as wood, metal and drywall. The two angled sides are helpful when sanding small details or getting-Inch to corners. Use it to smooth surfaces just before applying the first coating. 3M(TM) SandBlaster(TM) medium sanding sponges sand fast, last long and are clog resistant.