The manufacturer's part number 422650000 corresponds to the Smith & Wesson M&P 1.0 and M2.0 Shield pistols chambered in 9mm, .40 S&W, and .30 Super Carry. This recoil spring assembly is specifically designed for 3.1" barrel length and has an approximate length of 2 3/8". Contact us via email or phone for all your Smith & Wesson needs.