This is a BLR11096 3/8" Spot Weld Kit. 3 pc 3/8" Cutters Heavy Duty Spotweld Cutter Set. These annular tools cut clean, burr-free & round holes fast, unlike twist drills that push or hole saws that tear through materials. There's 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.