The W79 was an American nuclear artillery shell, fired from any standard 8 inch (203 mm) howitzer e.g. the M115. The W79 was produced in two models, the "W79 Mod 0" and "W79 Mod 1". Both were a plutonium-based linear-implosion, nuclear weapon. The "Mod 0" was a variable yield device with three yields, ranging from 100 tons up to 1.1 kiloton and an enhanced-radiation (popularly known as Neutron bomb) mode which could be turned on or off. Both models were 8 inches (203 mm) in diameter, 44 inches (112 cm) long and weighed 200 pounds (90 kg).