Strike Industries AR-10 Flat Wire Spring Black One Size. 308 AR system. The flatwire spring increases service life of the platform smooths out the shooting cycle and greatly outlasts the stock spring. Increased bolt load in addition to decreased compressing force increases reliability in cycling. Specifications for Strike Industries AR-10 Flat Wire Spring: Manufacturer: Strike Industries Color: Black Finish: Chrome-Silicon Fabric/Material: Cryo-cycled Steel Gun Model: AR-10 Condition: New Features of Strike Industries AR-10 Flat Wire Spring Cryocycled chromesilicon steel for strength reliability and longevity Decreased harmonics lessens system vibration for faster follow up shots. No more AR twang Compatible with all standard AR10/SR25 receiver extension lengths Package Contents: Strike Industries AR-10 Flat Wire Spring What firearm models does the manufacturer say Strike Industries AR-10 Flat Wire Spring is compatible with? The manufacturer says that Strike Industries AR-10 Flat Wire Spring is compatible with AR-10Strike Industries SI-AR10-FWS: AR-10 Flat Wire Spring Black One Size