V Assault Amphibious Vehicle (AAV)—official designation AAVP-7A1 (formerly known as Landing Vehicle, Tracked, Personnel-7 abbr. LVTP-7)—is a fully tracked amphibious landing vehicle manufactured by U.S. Combat Systems (previously by United Defense, a former division of FMC Corporation).
The AAV-P7/A1 is the current amphibious troop transport of the United States Marine Corps. It is used by U.S. Marine Corps Assault Amphibian Battalions to land the surface assault elements of the landing force and their equipment in a single lift from assault shipping during amphibious operations to inland objectives and to conduct mechanized operations and related combat support in subsequent mechanized operations ashore. It is also operated by other forces. Marines call them “amtracs”, a shortening of their original designation, “amphibious tractor”.
Vir: Assault Amphibious Vehicle on Wikipedia