Burglar alarm are used in residential, commercial, industrial, and military properties for protection against burglary (theft) or property damage, as well as personal protection against intruders. Burglar alarms protect the premises int the same sense as Car alarms protect vehicles and their contents. Prisons also use security systems for control of inmates. There is an old age saying that prevention is better than cure. If you believe in this saying, then you must have an intruder/burglar alarm installed in your home. Because it is useless to lock down the safe when the money is gone. Some alarm systems serve a single purpose of burglary protection; combination systems provide both fire and intrusion protection. Intrusion alarm systems may also be combined with closed-circuit.