The P.O. Mark III Anti-Zentraedi Rifle was a hand-held weapon developed during the First Robotech War by the scientists at Research Base Gibraltar. It was a particle-beam weapon with an 8-round energy magazine with it being equated to a hand-held Rail gun. The strength of the weapon meant it was able to deal a great amount of damage to a target and the impact round was loud for the eardrum.
Doctor Chase gave a demonstration of one of these weapons at scientific research facility armory in the asteroid belt. Rick Hunter later made use of one of these rifles during the Zentraedi assault on the research base. He managed to critically damage and destroy one of the Zentraedi Powersuits that were attacking the facility.