DIRECTED ELECTRONICS Protect your vehicle with an invisible sensing field which detects moving high-density objects (including people) near your car using Radio Frequency(RF) field disturbance technology.Protect yourvehicle with an invisible sensing field which detects moving high-density objects (including people)near your car using Radio Frequency (RF) field disturbance technology. Ideal for convertibles, or any application where zone-intrusion protection isdesired. Violation of the outer field can provokesiren chirps (or a WarnAway? message from an optional voice module) while intrusion into the inner zone will trigger the system?s siren.