Army - Avenger Air Defense Artillery without Text - T Shirt - ClassicThe Avenger Air Defense System, designated AN TWQ 1 under the Joint Electronics Type Designation System, is an American self propelled surface to air missile system which provides mobile, short range air defense protection for ground units against cruise missiles, unmanned aerial vehicles, low flying fixed wing aircraft, and helicopters. The Avenger was originally developed for the United States Armed Forces and is currently used by the U. S. Army.