There is a variant of the P90 in the Rainbow Six universe. The P90 features an integrated reflex sight and a unique magazine that holds 50 rounds, loads from the top and ejects the casings out of the bottom of the weapon's stock. The P90 was made as the companion weapon to the Five-seveN, since they both chamber the same round. The P90 is a compact bullpup PDW (Personal Defense Weapon) designed in the 1990s and manufactured by FN Herstal that chambers the 5.7x28mm round.