Atlas Gunworks Color Coded Recoil Spring 11lb 4.6"

Atlas Gunworks 4.6" Spring Compatibility: Hyperion Athena Chaos Precut for our 4.6" Pistols Limited 9mm (Minor PF): Replace every 10k rounds* Limited 40SW (Major PF): Replace every 8k rounds* Open 9mm/38SC (Major PF): Replace every 5k rounds* *OR if they loose more than .5lb of pressure, (your spring that used to be 8lb is now 7.5lb), whichever comes first!