Real steel history: The P90 is a Belgian designed 5.7x28mm submachine gun, developed between 1986–1987 by Stéphane Ferrard at Fabrique Nationale de Herstal. The weapon’s name is an abbreviation of Project, and the number 90, which specifies a weapon system of the 1990s.
The P90 TR features a receiver-mounted triple MIL-STD-1913 rail interface system or "Triple Rail" (TR). There is one full-length rail on the top of the base and two rail "stumps" on both sides of the receiver. The side rails serve as mounting points for tactical accessories such as laser pointers or halogen flashlights, while the integrated top rail will accept various optics with no tools or additional mounting hardware required. Some components of the P90 TR and standard P90 are not interchangeable since the entire receiver assembly is different.
The P90 TR is considered a Personal Defense Weapon (PDW), and is designed as a compact but powerful firearm for vehicle drivers, operators of crew-served weapons, support personnel, special operators and anti-terrorist units.