Israel developed ERA in the 1970s, and were the first to use it successfully in combat during the 1980s. The ERA will make the armored vehicles about 24 inches wider. The ERA being provided now is considered third generation, and more reliable and effective than earlier versions. The current ERA can also handle tandem warheads, which could get through earlier versions of ERA. The U.S. Marines began putting ERA on some of their armored vehicles during the 1990s. The only downside of ERA is that, when it goes off, it throws off small metal fragments, along with those created by the RPG or missile that set them off in the first place.
An Israeli firm (RAFAEL) is supplying the U.S. Army with ERA (Explosive Reactive Armor) kits for M-1 Bradley and Stryker armored vehicles. ERA consists of blocks of explosives, encased in thin metal containers, that explode and neutralize anti-tank rocket and missile warheads. ERA contains sensors that detonate when hit with a missile or shell. The 4.3 ton kits cost $300,000 each. Bradleys are getting the new ERA kits this year, Stryker will begin getting it next year.