Griffin Armament Buffer Spring M4 Black Large GABSM4. Griffin's buffer springs manufactured from 17-7 stainless steel wire offer excellent resistance to corrosion superior fatigue properties and exceptional rigidity and durability. These springs are standard weight springs- identical to the highest quality mil-spec 17-7 derivatives. Specifications for Griffin Armament Buffer Spring: Manufacturer: Griffin Armament Color: Black Finish: Corrosion Resistant Fabric/Material: 17-7 Stainless Steel Gun Type: Rifle Package Contents: Griffin Armament Buffer Spring What firearm models does the manufacturer say Griffin Armament Buffer Spring is compatible with? The manufacturer suggests that Griffin Armament Buffer Spring is compatible with AR-10 M4Griffin Armament GABSM4 : Buffer Spring M4 Black Large