IRWIN HANSON Spiral Flute Screw Extractors, 6 Piece Set, 53545 Designed to remove broken studs, bolts, socket screws, and fittings Aggressive left hand spiral design for extra gripping power Easy out style spiral flutes embed themselves to increase grip as resistance increases Extractor size and recommended drill bit size are etched on each tool Set includes spiral flute screw extractors sizes EX-1, EX-2, EX-3, EX-4, EX-5, and EX-6