The GfS Day Alarm is a quick and easy method of securing emergency exit doors. Simply install the radio reed contact to the door and plug in the alarm system either at the door or in the security office and your door is secured. In an emergency situation the users can use the door as usual. Authorized persons can allow a single passage, a longterm passage or activate the alarm. If the door is left open beyond a predetermined length of time this condition will trigger the alarm.