... every zone could connect with 10 sensors 4. LCD display Wireless GSM Security Alarm SystemsFunction Instruction:1) Built- ... zone can add 10 sensors;3) LCD screen with time clock display;4) Voice prompt for all operations; ... , door, hall, window, balcony, and perimeter places alarm;15) Real-time, delay, 24 hours, bypass Defence zones programming ... Wireless GSM Security Home Alarm System with LCD Display