The Irwin Bolt-Grip extractors are designed to easily remove broken, damaged or rusted nuts, bolts, and screws. These bolt extractors feature reverse spiral flutes designed to bite down and provide maximum gripping power, and they are made from high-carbon steel for durability and long life. The universal lobular design fits all types of fasteners. Irwin Bolt-Grip 5-Piece Expansion Set, No. 394002, is made with a 3/8" square drive, and includes extractors to remove bolt sizes: 8mm, 10mm, 13mm, 19mm, 5/16", 11/16" and 3/4".