... alarm system use.high quality Contain keyboard,buit-in power,recording model;CONTACT ID, ADEMCO4+2 communication protocol; Alarm receipt center,telephone,local alarm ... monitor, 12V7/AH battery, at most connnect 4 keybaord. Timing defense and withdrawal, forced defense, individual dedense and withdrawal; Control ... alram to ring with telephone, blackout alarm in AC, defese ...