Introduced in 2004, the real steel PX4 Storm is a polymer pistol with many components and layout features seen on older weapons but is itself a radical departure from the manufacturers other pistols. Perhaps that's a reason why the PX4 was used in the hit movie INCEPTION.
For the brand new Marui PX4, a 25 round magazine; capable of running on HFC134a or Green / Top gas but does not have the valves or seals to handle red gas or CO2.