24 hours a day reliable safety & convenience for your house and office. DIY design, no wiring need, and all functions by keypad access code control. 10 meters range with wide detection angle. Battery operated with DC adapter optional. Built-in powerful alarm sound up to 120 db. Intrusion Warning- Once the unit has been triggered in the last alarm period, the unit will beep inside of LED flashing during the entry delay time. This indicates that the alarm has been activated. This also means that the intruder has intruded before. Panic Alarm - In the event of an emergency, an immediate alarm can be made by simultaneously pressing the "F" and "Lock" key, the alarm will sound for 30 seconds.