A top attack device is designed to attack armoured vehicles from above, as the armour is usually thinnest at the top. Ideally, it will penetrate perpendicular to the attacked surface. The device may be delivered (often as a submunition) by a missile, artillery shell, or even an emplaced munition. Top attack munitions use either a high explosive anti-tank (HEAT) warhead for direct impact or near impact, or an explosively formed penetrator (EFP) warhead for over-flight of the target.