Tamiya 35071 1/35 M577 Armoured Command Post Carrier

Vietnam War
U.S.
M577 - command variant, carries additional radios and a generator.
M113 - original version, V8 gasoline engine.
M113A1 - starting in 1964, the gasoline engine was replaced with diesel engine.
M113A2 - in 1979, further upgrades, armored fuel tanks. Four-tube smoke grenade launchers.
M113A3 - in 1987, enhanced battlefield survival.