Beretta Px4 Storm Pistol Magazine .40 S&W 17 Round Black 1 Pack Steel JM4PX4017-17RD. It is also compatible with these other Beretta models: Cx4 Storm with Px4 magazine well insert/magazine release Px4 Compact and Px4 Sub-Compact. Note: If you are purchasing this magazine for a CX4 Carbine please ENSURE that your pistol has a compatible adapter. Specifications for Beretta Px4 Storm .40 S&W 17 Round Pistol Magazine: Manufacturer: Beretta Gun Make: Beretta Caliber: .40 S&W Magazine Capacity: 17 Round Color: Black Fabric/Material: Stainless Steel Package Contents: Beretta Px4 Storm .40 S&W 17 Round Pistol Magazine Beretta JM4PX4017-17RD: Px4 Storm Pistol Magazine .40 S&W 17 Round Black 1 Pack Steel