This blued alloy steel 17-round 9mm Luger Genuine Ruger Factory Magazine is compatible with the Security-9 pistol and the PC Carbine with the SR9/Security-9 Magazine Well Insert installed. This magazine comes with a flush-fit floorplate installed and an adapter in the box for use in the standard Security-9. Not recommended for use with the Security-9 Compact. It is not compatible with the SR9 or SR9c pistol.