is a 105-mm tandem shaped charge with a weight of 10.3-kg (22.7-lb) and has a range of 200 meters and a stated penetration capability in excess of 600-mm (24-in) rolled homogeneous armor (RHA) (after ERA), 1500-mm reinforced concrete, 2000-mm brick and 3700-mm of soil. Reactive armor, including explosive reactive armor (ERA), can be defeated with multiple hits into the same place, such as by tandem-charge weapons, which fire two or more shaped charges in rapid succession. Protection An early method of disabling shaped charges developed during World War II was to apply thin skirt armor or meshwire at a distance around the hull and turret of the tank. The skirt or mesh armor (cage armor) triggers the RPG on contact and much of the energy that a shaped charge produces dissipates before coming into contact with the main armor of the vehicle. Well-sloped armor also gives some protection because the shaped charge is forced to penetrate a greater amount of armor due to the oblique angle. The benefits of cage armor are still considered great in modern battlefields in the Middle East, and although similar effects can be obtained using spaced armor, either as a part of the original design or as appliqué armor fitted later, cage armor is preferable due to its low weight and ease of repair. Today, technologically advanced armies have implemented composite armors such as Chobham armour, which provide superior protection to steel. For added protection, vehicles may be retrofitted with reactive armor; on impact, reactive tiles explode or deform, disrupting the normal function of the shaped charge. Russian and Israeli vehicles also use active protection systems such as Drozd, Arena APS or Trophy. Such a system detects and shoots down incoming projectiles before they reach the vehicle. As in all arms races, these developments in armor countermeasures have led to the development of RPG rounds designed specifically to defeat them, with methods such as a tandem-charge warhead, which has two shaped charges, of which the first is meant to activate any reactive armor, and the second to penetrate the vehicle. Weapons by country Soviet Union and Russian Federation Specific types of RPGs (current, past and under development) include: Anti-personnel explosives RPG-7: Reloadable RPG launcher, TBG-7V thermobaric rocket and OG-7V fragmentation grenade RPG-27 "Tavolga": One-shot disposable RPG launcher, RShG-1 thermobaric rockets RShG-1 RShG-2 RPG-29 "Vampir": Reloadable RPG launcher, TBG-29 thermobaric rockets RPO Rys RPO-A Shmel MGK