The M72 LAW is a portable one-shot 66-mm unguided anti-tank weapon. In early 1963, the M72 LAW was adopted by the U.S. Army, U.S. Marine Corps and Air Force as their primary individual infantry anti-tank weapon, replacing the M31 HEAT rifle grenade and the M20A1 "Super Bazooka" in the U.S. Army. It was replaced by the M136 AT4 in 1987.