... OMD mobile call GSM alarm system,home guard gsm sms alarm system,wireless calling system,gsm auto dialalarm system,gsm alarm system wireless alarm system,gsm alarm systemFeatures: 1. ... , then play the greeting back;7. Arm/Disarm the system by 5ways: SMS, Main Host(Keypad), Wirless keypad, ... external power supply. 13. Store up to 99 alarm records and 99 arm/disarm records. SMS alarm GSM alarm system