Explosive reactive armor (often shortened to ERA) is a variant of reactive armor for vehicles that consists of a sheet or slab of high explosive sandwiched between two plates, typically metal, which detonates on attack by a penetrating weapon, forcibly driving the metal plates apart to damage the penetrator.
Explosive reactive armor has been valued by the Soviet Union and its now-independent component states, especially the Russian Federation, since the 1980s; almost every armored vehicles in their military inventory today has either been manufactured to use ERA or had ERA tiles added to it.
Manufactured and stored in the Russian Industrial Plant, explosive reactive armors can be installed on Russian tanks upon command, which makes them more resistant against anti-tank weapons, such as rockets, explosives and tank shells.