The PS90 USG offers a non-magnifying black reticle optical sight module while the PS90 TR features three MIL -STD 1913 mounting rails. Chambered in the high velocity 5.7x28mm cartridge, the PS90 utilizes blowback operation and fires from a closed bolt for greater accuracy and reliability. The PS90’s 16.04" cold hammer-forged MIL -SPE C barrel is equipped with an integrated muzzle brake to reduce recoil. Models with 10- or 30-round polymer detachable magazines are available. The PS90’s safety switch is located inside the trigger guard for easy access. Dual magazine latches, cocking handles and an innovative synthetic thumbhole stock with a molded-in sling attachment point help make the PS90 fully ambidextrous.