Ed Brown 15 lb Flat-Wire Recoil Spring Fits Smith & Wesson M&P

Designed for M&P 4 inches, 4.25 inches and 5 inches models, the Ed Brown Fueled M&P recoil spring offers exceptional durability. With a 15# recoil spring, it delivers up to ten times the lifespan of standard coil springs and it's recommended to replace it after 30,000-40,000 rounds for optimal function.