Product Description The FailZero EXO Bolt Assembly is a fully assembled bolt built for 5.56/.223 AR-pattern rifles and designed to work with most mil-spec AR-15, M16, and M4 bolt carrier groups. Finished with FailZero EXO Nickel Boron (NiB), this bolt assembly delivers permanent dry lubricity to reduce friction, helping improve cycling performance while making cleanup faster and easier. The NiB treatment also adds enhanced wear and corrosion resistance for long-lasting reliability. Product Highlights EXO Nickel Boron (NiB) coating for permanent dry lubricity and reduced friction Compatible with most mil-spec AR-15, M16, and M4 carriers 5.56/.223 bolt assembly supplied fully assembled for straightforward replacement Enhanced wear resistance for extended service life under hard use Corrosion-resistant finish supports easier maintenance and cleaning Specs Brand: FailZero Product Type: Bolt Assembly Caliber Compatibility: 5.56 NATO / .223 Remington Carrier Compatibility: Most mil-spec AR-15, M16, and M4 carriers Finish/Coating: EXO Nickel Boron (NiB) UPC: 881314861873 Manufacturer Part Number: EXO-BOLTASSEMBLY01 Disclaimer: We strive to provide accurate and up-to-date product descriptions, specifications, and images; however, errors or omissions may occasionally occur. We are not responsible for any inaccuracies or discrepancies in the content provided. If you notice anything incorrect or unclear, please contact us so we can correct it. When in doubt, we recommend verifying details directly with the product&&';;s manufacturer.