It detects intrusion, fire, burglary, and carbonmonoxide presence.
The alarm alerts you to a problem with a very loudbeepand in some cases, is accompanied by brightflashing lights.
Features also include, it beeps when doors or windows are opened.
Fire alarm sensors are of three general categories: smoke, flame and heat.
Safety detectors include thermostats for detecting excessively high temperatures, water sensors for flooding, excessive carbon monoxide concentrations etc.
It can be activated and deactivated with either a simple turn of the key or a key pad control panel.
Door alarms are relatively inexpensive and reliable.
You no longer have to hire an electrician to run the wires through the ceiling or walls. Hence, many people now install their own door alarms.