A remote weapon station, also known as a remote weapon system, (RWS) is a remotely operated weaponized system for light and medium caliber weapons which can be installed on ground combat vehicle or sea and air-based combat platforms. Such equipment is used on modern military vehicles, as it allows a gunner to remain in the relative protection of the vehicle. It may also be retrofitted onto existing vehicles, for example, the CROWS system is being fitted to American Humvees and the Thales SWARM for Bushmaster IMVs of the Royal Netherlands Army. An early version of the concept, based on the MG 34 and aimed using an optical periscope, was mounted on German assault guns and tank destroyers during World War II.