It's got plenty of names - "Old Man", "Screw Knocker", and "Woodpecker" - but this extractor gets results when loosening and removing corroded and over tightened screws and other fasteners. The extractor's 0.401 shank fits into a rivet gun, which delivers a high paced pulse that breaks hardware free without damaging the surrounding materials. Includes a wrench and 3/8" drive, 1/4" bit apex holder. Overall length is 8".