The AGM-158 Joint Air-to-Surface Standoff Missile is a low detection standoff air-launched cruise missile developed by Lockheed Martin for the United States Armed Forces. It is a large, stealthy long-range weapon with a 1,000-pound (450 kg) armor piercing warhead. It completed testing and entered service with the U.S. Air Force in 2009, and has entered foreign service in Australia, Finland, and Poland as of 2014. An extended range version of the missile, the AGM-158B JASSM-ER, entered service in 2014 as well as an anti-ship derivative, the AGM-158C LRASM in 2018.