Omega Old Man Screw Knocker OM54S 4” is known by many different names, ”Old Man”, ”Screw Knocker”, and ”Woodpecker”. Omega Old Man Screw Knocker OM54S 4” is an extractor that gets results by loosening or removing stubborn, corroded, or over tightened screws and other fasteners. Omega Old Man Screw Knocker OM54S 4” features a 0.401 shank that fits into a rivet gun which delivers a high paced pulse that breaks hardware free without damaging the surrounding materials. Omega Old Man Screw Knocker OM54S 4” accepts a 3/8” drive bit holder that is not included.