This Non Blow-Back Swiss Arms P92 replica in 4.5 mm is full metal, that is to say that it takes all the metal parts of the real weapon from which it is inspired.
This NBB pistol uses CO2, a gas perfectly suited to propelling 4.5 mm steel balls.
The breech being fixed, the mechanical constraints are largely reduced to favor a great autonomy (more than a hundred shots before changing the CO2 capsule!) and to preserve the durability of the replica.