Removes Broken Studs, Bolts, Socket Screws, And Fittings. Aggressive Left Hand Design Creates Extra Gripping Power. Easy Out Style Spiral Flutes Embed Themselves To Increase Grip As Resistance Increases. Extractor Sizes And Recommended Drill Bit Sizes Etched On Each Tool. Removes broken studs, bolts, socket screws, and fittings. Aggressive left hand design creates extra gripping power. Spiral flutes embed themselves to increase grip as resistance increases.