Product Description The FailZero Basic Semi Kit Bolt and Hammer is a complete, fully assembled bolt carrier group (BCG) with semi-auto hammer, designed to drop into most mil-spec AR-15 upper receivers. Critical components are treated with FailZero EXO Nickel Boron technology to provide permanent dry lubricity, extreme durability, and improved wear and corrosion resistance for smoother cycling and easier maintenance. Product Highlights Fully assembled AR-15 bolt carrier group for quick, drop-in installation in most mil-spec upper receivers Includes semi-auto hammer for a complete basic semi kit setup EXO Nickel Boron treated critical parts for permanent dry lubricity and reduced friction Enhanced wear resistance and corrosion resistance for long-lasting performance Nickel finish for a clean, low-friction surface that helps simplify cleaning Specs Product Type: Bolt Carrier Group (BCG) with semi-auto hammer Coating/Finish: EXO Nickel Boron (Nickel) Compatibility: Most mil-spec AR-15 upper receivers UPC: 881314861880 Manufacturer Part Number: FZ-AR15-01-SAH Brand: FailZero 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 products manufacturer.