TheDura-Grit 9" Carbide Flat Sander 120 Grit are powerful sanding devices, thin enough to get into tight spaces and strong and durable enough to handle the toughest jobs. They are more aggressive and longer lasting than regular files. Well suited for sanding in hard to access spaces. The Dura-Grit 9" Carbide Flat Sander 120 Grit cuts forwards and backwards. When you are filing with this tool, the work time is effectively reduced by half.