Each stripped bolt extractor set is made of high-hardness chrome-molybdenum steel for superior durability and longer life. It will easily extract damaged bolts, nuts, and screws, even if they are stripped, rusted, or frozen | The internal thread with reverse spiral flutes is designed to bite down for maximum gripping power. The more you turn, the tighter the bolt extractor socket set grips | The standard 3/8-inch square drive and hex adapter make the lug nut extractor set compatible with hand, air, or power tools | 18 pieces 3/8 inch drive stripped lug nut remover includes 3/4"(19mm), 11/16", 17mm, 5/8"(16mm), 9/16", 14mm, 13mm, 1/2", 12mm, 7/16"(11mm), 10mm, 3/8", 9mm, 5/16"(8mm), 7mm, 1/4", hex adapter and knockout pin | The heavy-duty blow-molded case is for bolt remover and extractor organized storage and easy carry