M19-B surface-to-air missile launcher
From Halopedia, the Halo wiki
Template:Weapon The M19B Surface-to-Air Missile Launcher is a man-portable anti-aircraft weapon used by the United Nations Space Command.[1]
The M19B SAM launcher fires surface-to-air missiles, presumably M19 HEAT shaped charge rockets, which can easily destroy Type-26 Banshees; however, the weapon causes little damage to Type-31 Seraph fighters due to their energy shielding and heavy armor.[1]
Though the weapon is quite powerful, it is not frequently deployed.[1] This is likely because its more common counterpart, the M41 Surface-to-Surface Rocket Medium Anti-Vehicle/Assault Weapon, can also serve as a potent anti-aircraft weapon.