Drill-Out® Power Bolt Extractor Kit - 4-PcDrill-Out®is a drill bit and extractor in one. The drill bit is made from high quality heat treated steel - allows you to drill into even Grade8 and stainless steel bolts. The extractor is made from hard,flexible die steel which allows it to bite into any bolt or stud without slippng or stripping. Uses the power of your drill to extract the bolt. Only requires shallow drilling depth so there is less chance of going off-center and less drilling time. Specially designed drill tip will not walk or wander. Includes four sizes: 1/4"-6mm, 5/16"-8mm, 3/8"-10mm and 1/2"-12mm. Carrying case included.