The full size and Compact versions have a spring-loaded disassembly bar, accessed via recesses on both sides of the frame, which must be grasped and pulled down to release the slide.

The magazine holds the top round directly behind the barrel's breech end so only a slight feed ramp is needed.

The Px4 originally featured an interchangeable, luminescent 3-dot sight system (coated in Super-LumiNova) for use in dark or low-light situations.

These parts include the backstrap, the magazine release button, the slide catch, the safety/decocker levers, and the hammer unit mechanism.

The magazine release button can be mounted on either side of the weapon and replaced by one of three types: standard, large or combat (extended).

The standard slide catch and the safety/decocker levers can be replaced with slimmer versions to avoid snagging when the weapon is drawn quickly from a holster.

Like the 9000S but unlike the Px4 full size and Compact, Px4 Subcompact uses a tilt barrel system and a rotating takedown pin.

Although the Subcompact is different from the larger versions in terms of its operation, it shares some interchangeable parts with the full size and the Compact, such as the safety levers, trigger, and magazine release buttons.

[6][7] The Px4 Compact Carry is a Type G model (with low profile decocker levers) available in 9mm luger caliber, includes a larger magazine release button.

It has a reinforced body and is slightly larger than the 9mm / .40 S&W full size pistols to handle the higher ballistic power of the .45 ACP cartridge.

The Px4 .45 ACP is available as a standard black model and as a Special Duty model with desert tan frame color, PVD coated magazines and internal firing control assembly, double recoil spring, and a longer barrel that extends beyond the slide.