Product Description Made in the USA, the ProMag PM237B Magazine Quick Change Adapter Block is designed to install into AR-15/M16 lower receivers to enable the use of 9mm Colt/SMG-type magazines when paired with a 9mm upper receiver. The adapter block features a high-strength polymer body with steel hardware and critical steel components including the roller, ejector, and bolt stop. Its improved design supports quick installation without needing to remove the bolt stop roll pin, making it a practical choice for AR 9mm conversions and setups that require fast, non-permanent compatibility changes. Product Highlights Converts AR-15/M16 lower receivers to accept 9mm Colt/SMG-style magazines when using a 9mm upper receiver Quick-change design allows installation without removing the bolt stop roll pin High-strength polymer construction with steel hardware for durability and long service life Includes steel roller, ejector, and bolt stop components for reliable function Made in the USA with a black finish for a clean, factory-style look Specs Brand: ProMag Product Type: 9mm magazine adapter block (quick change) Compatibility: AR-15 / M16 lower receivers; for use with 9mm upper receivers Magazine Fit: 9mm Colt/SMG-type magazines Material: High-strength polymer body with steel hardware Steel Components: Roller, ejector, bolt stop Color/Finish: Black Country of Manufacture: USA Manufacturer Part Number: PM237B UPC: 708279013805 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.