A crew-served weapon is any weapon system that is issued to a crew of two or more individuals performing the same or separate tasks to run at maximum operational efficiency, as opposed to an individual-service weapon, which only requires one person to run at maximum operational efficiency. The weight and bulk of the system often also necessitates multiple personnel for transportation. Crew-served weapons operated by infantry include sniper rifles, anti-materiel rifles, machine guns, automatic grenade launchers, mortars, anti-tank guns, anti-aircraft guns, recoilless rifles, shoulder-launched missile weapons, and static anti-tank and anti-aircraft missiles.