POWERTEC 4 x 36 in. Aluminum Oxide Sanding Belt for Belt Sander. This premium pack of 3 or 10 was designed to provide you with a cost effective set of long lasting and high performance sanding belts. Made with open coat Aluminum Oxide (A/O) grain, they act as a multi-purpose tool best used for wood sanding, shaping, stripping and giving a smooth finish to many of your woodworking applications. Additionally, these belts work exceptionally well with lite and non-ferrous metals, blending welds, fiberglass, plastic, and rubber. Each belt flaunts an X-weight clothed backing, and possesses a strong resin on resin bond with well crafted seams for long lasting results. Grit Selection Guide: //40 - 60 Grit: Sandpaper is fairly coarse - Heavy Sanding and Stripping. //80 - 180 Grit: Sandpaper is fairly medium - Removing Tiny Imperfections. //240 - 400 Grit: Delivering a Super Fine Smooth Finish.