Product Description The LBE Unlimited M16BLT is a complete M16-style bolt carrier group (BCG) that comes assembled and ready to install. Built around a phosphated 8620 steel carrier, it features a chrome-lined carrier interior and a chrome-lined gas key for durability and easier cleaning. The included Carpenter 158 bolt comes with the extractor and bolt gas rings, and the gas key screws are staked to help maintain reliability under use. Product Highlights Complete, assembled M16-style bolt carrier group (BCG) ready for installation Phosphate-coated 8620 steel carrier for proven wear and corrosion resistance Carpenter 158 bolt with extractor and bolt gas rings included Chrome-lined carrier interior and chrome-lined gas key for longevity and easier maintenance Staked gas key screws to help maintain proper gas system function Specs Brand: LBE Unlimited Manufacturer Part Number: M16BLT UPC: 765857617305 Product Type: Complete Bolt Carrier Group (BCG) Style: M16 / M16-style Compatibility: AR platform (M16-style / AR-15 fitment noted by retailer listings) Caliber: 5.56x45mm NATO Carrier Material: 8620 steel Finish: Black phosphate Bolt Material: Carpenter 158 Lining: Chrome-lined carrier interior; chrome-lined gas key Country of Manufacture: USA 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.