Part# 27128 Wolff Precision Gun Springs delivers enhanced extraction reliability for Smith & Wesson firearms. This 10 LB XP Extractor Spring—engineered to exceed the factory 9-pound specification—is precision-manufactured for optimal performance in numerous S&W models including 457, 645, 745, 4505, 4506, 4516/4516-1, 4526, 4536, 4546, 4556, 4566, 4576, 4586, 4596, 1006, 1026, 1066, 1076, 1086, 4013, 4014, 4053, 4054, and compatible .45 ACP variants. Sold individually.