The P90 is a selective personal defense weapon, designed and manufactured by FN Herstal. The P90 fires FN high velocity 5.7 x 28mm rounds.
The P90 does't appear in campaign, instead, it is only available in multiplayer.
It has a high rate of fire, low recoil, and high magazine capacity, but medium damage. Rather than its stock iron sights, it utilizes what is known in-game as mini reflex sight, which is slightly smaller than the normal Red dot sight (holographic sight in fact), but also somewhat harder to aim due to the transparency of the red dot. It burns through ammo considerably fast, emptying its magazine in less than five seconds. It is unlocked at rank 9 of the Special Ops class.