Replacement or spare magazine for your 9 mm Px4 Storm, 10 round capacity. Caliber: 9mm. Finish: Black Also compatible with: CX4 with PX4 Magazine Well Insert/Magazine Release, PX4 Full Size 9MM, PX4 Compact 9MM, PX4 Sub-Compact 9MM* (Will extend below the base of the grip on a Compact and Sub-Compact) Specifications: Caliber: 9mm. Finish: Black Capacity: 10 Round PX4 Full Size