The Poolguard Door Alarm DAPT-2 installs beside any door that provides access to your swimming pool. Doors that allow young children quick, easy entry to pool areas pose a safety risk and require a door alarm. This model includes two magnetic switches, hook-up wire, and runs on a single 9-volt battery. The alarm features a delay switch that allows adults to pass through without triggering it.The door alarm will sound in 7 seconds when a child opens the door. The alarm will continue to sound until an adult comes to the door and resets the alarm. Even if a child goes through the door and closes it behind them, the alarm will sound.The door alarm is always on and will automatically reset under all conditions. The alarm is equipped with an adult pass-through feature that allows adults to go through the door without triggering the alarm. The Poolguard Door Alarm uses one 9–volt battery (not included) with a battery life of approximately 1 year. The alarm features a low-battery indicator that audibly alerts you when your battery is low. Poolguard has the only door alarm listed under UL 2017 for water-hazard entrance alarm equipment.Very easy to install, this alarm can also be installed on sliding glass doors.