Stern Def. Magazine Adapter Ad9 S&W M&P/Sig P320 9/40 Mags Type/Color: 9MM Magazine Adapter Size/Finish: For 5.56MM Lower Material: Aluminum AR-15 Accessory: Y Made In The USA: Made In The USA Other FEATURES:: Must Be Used With A 5.4 Ounce Buffer Or HEAVIER When USING A Carbine Spring. Buffer Not Included. Other FEATURES2:: Allows Standard Mil-Spec AR-15 LOWERS To Accept 9MM And 40S&W S&W M&P Series And Sig P320/P250 MAGAZINES, Requires A for Glock Cut Bolt Manufacturer: Stern Defense Model No: 001-Sd Mag-Ad-MP-9And40/P320-M