This is a BLR11082 Premium Spotweld Cut Kit. This is a 3 pc 3/8" Cutter's Spot Well Cutter Set. Made of high speed steel, these annular tools cut clean, burn-free & round holes fast unlike twist drills that push or hole saws that tear through materials. There is no dead zone, so less thrust is required & no deforming of stock or jagged edges occurs. The cutters are for the heavy-duty use in sheet metal & materials up to 1/2" thick. Multiple cutting teeth, precision ground which allows for a long tool life. These cutters are packaged in a plastic carrying case.