... when alarm 3, two-way communication for alarm gsm alarm security system1, know which zone and ... voice communication. 4.The system supports the GSM cell phones, no need the fixed telephone line. 5 ... 160pcs in total. 12.Send the SMS to GSM alarm system to program, it is very easy ... output relay, can control the home applianceStandard components1 gsm alarm security system main panel1 wireless PIR detector1 ...