... , ISO9001:2000 Main features:Use SIMCOM GSM module----industrial module. Two-way voice communication, to speak with people who are on spot ... back-up battery, when the power is off, it still can work about 24 hours.Has output relay, can control home appliance ... – 1pc- Adaptor--1pc- Installation/user manual – 1pc.We are the manufacturer of home gsm alarm system, alarm system, wireless alarm, home alarm ...