The flat wire spring for 1911 handguns is a must for any handgun enthusiast or full time shooter. Manufactured from Chrome Silicon alloy to maximize spring longevity and load. The longest lasting handgun recoil spring made – up to ten times greater service life than a conventional coil spring. Other benefits of switching from conventional round wire to flatwire include improved cycling and more tolerant to a wider variety of loads. Intended for use with our flat wire guide rod system. Recommended spring replacement at 30,000-40,000 rounds. Will not work with a standard recoil spring guide and plug, only the flat wire guide rod and plug.