... D fire alarm system,gsm alarm system,gsm alarms,wireless alarms,wireless alarm system,intruder alarm system,intruder alarms,gsm industry alarm system,gsm power ... unit at any time and listen what happened in the alarm area. 6. Arm/disarm by wireless keyboard or phone ... with intercom. 10. Switch to Backup rechargeable battery when power is failure or cut by intruder. 11.Wireless signal transmission, and ...