Rennsteig Dual-edged (Easy Out, Bolt Extractor) New and Patented Design!!! Screw Extractors for RIGHT HAND THREAD and LEFT HAND THREAD 5-piece Set in Plastic Tube For unscrewing ruined screws and bolts without damaging threads Made of high-strength steel (chrome vanadium) for greater resistance to breaking and rounding out Can be turned in clockwise or counterclockwise direction (for right-and left-hand threads) Non-slip and dual-edged engagement with the screw or bolt to be removed To see how it works look at http://www.youtube.com/watch?v=wBfbrUFeaDI