The highest quality recoil springs from ISMI in 16lbs. Will work with most 1911 spring guide rods to tune your recoil system to the load and the feel you prefer.

Also fits full size Springer Precision Sig P320 and P320 X5 1911 guide rods.

These work with 4.5″ and 5.25″ Springfield XDM models and 5″ XD models, if you are using it on a 4″ XD model you will need to trim your springs.