The Defense Department is ready to deploy its version of a stun gun based on gyrotron energy beam technology. Procurement of the nonlethal weapon has been incorporated into the Pentagon's budget planning cycle. Called the Active Denial System, the gyrotron energy beam is DoD's first nonlethal, anti-personnel, directed-energy weapon. The millimeter-wave energy beam works by heating the skin's surface, invoking an involuntary "flee" response. The beam is less powerful than a microwave beam. The weapon will be adapted for use on tanks and other ground vehicles as well as ships and aircraft.