13-Piece Bolt Extractor SetLeft hand spiral flute for gripping power. Can be used with flat wrench, adjustable wrench or socket. Made with high carbon steel. Available in 18 sizes from 1/4"-1" standard & metric. Drive Size: 3/8 in; Quantity: 13 per set; Size: 1/4 in [Min], 3/4 in [Max]; Weight: 1.74 lb.