It was seen in Taken 2.
The Px4 uses the same short-recoil, rotating barrel action as the Beretta 8000 Models and uses the same trigger and safety system as the M9/92/96 series, while being completely different in design from either. Light-weight polymer construction with steel inserts, a modular trigger group, fully enclosing slide, Picatinny rail, and changeable backstrap options for the grip are a radical departure from previous Beretta designs.Unlike the first generation Beretta 92/96/M9 series, the Px4's trigger guard is rounded for better concealed carry. The takedown pin of earlier models is replaced by a spring-loaded bar, accessed via frame recesses on both sides, which must be grasped and pulled down simultaneously to release the slide. The slide spring is doubly captive, being inserted approximately an inch into the transfer block at one end and a receiving hole in the front of the slide at the other. It is a self-contained assembly, completely captured by the polymer guide. The magazine holds the top round directly behind the barrel's breech end so only a slight feed ramp is needed. This allows the barrel to fully support the case. The 6-R rifling of the barrel generates counter-clockwise torque which is harnessed by the locking system to reduce the amount of pressure required from the rotating barrel lock's cam and pin system to effect unlocking. The steel transfer block's cam pin is 5 mm wide and 2 mm deep. The entire hammer unit mechanism can be removed from the Px4, without the use of special tools, as a single group. This allows easy access to the firing mechanism for cleaning. The Px4's design makes it impossible to assemble incorrectly from a field-stripped takedown.
The Px4 features an interchangeable, luminescent 3-dot sight system (coated in Super-LumiNova) for use in dark or low-light situations. With short exposure to any kind of light, the night sights' luminescence lasts up to 30 minutes. The weapon also incorporates a Picatinny rail under the muzzle to allow flashlights, laser sights, and other accessories to be attached. Beretta discontinued the luminescent 3-dot night sights for the Px4 in 2010, replacing them with standard 3-dot sights.