Product Description The Stern Defense Mag-AD9 magazine adapter converts a standard mil-spec AR-15, M4, or M16 lower assembly to run 9mm and .40 S&W magazines, including compatible M&P and Sig P320/P250 magazines. Designed to install in seconds, the Mag-AD series features a last round hold open function for improved handling and convenience. Built from aircraft-grade aluminum with a durable black finish, it&';s a practical upgrade for range use, training, and duty-oriented setups. Product Highlights Converts mil-spec AR-15 / M4 / M16 lower to accept 9mm and .40 S&W magazines Compatible with M&P and Sig P320/P250 magazines for broad magazine options Last round hold open feature for enhanced functionality Installs in seconds for fast setup and easy removal Aircraft-grade aluminum construction with black finish for strength and durability Specs Brand: Stern Defense Model/Series: Mag-AD9 Caliber Compatibility: 9mm, .40 S&W Magazine Compatibility: M&P; Sig P320/P250 Platform Compatibility: Standard mil-spec AR-15 / M4 / M16 lower assembly (5.56mm lower) Material: Aircraft-grade aluminum Color/Finish: Black Weight: 0.6000 lb Dimensions (L x W x H): 6.7000 x 4.4000 x 3.4000 in UPC: 850001176217 Manufacturer Part Number: 001SDMAGADMP9AND40/P32 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.