... 3,Voice prompt function 1, PSTN & GSM, Voice prompt function ,the use of industrial GSM / GPRS communication module 850/900/1800/ ... or cell phone can be controlled live arm, disarm, monitor, intercom, a / wireless appliance control output, system settings and other ... field, and so on, wired telephone networks can not reach. GSM security alarm system with LED display and keyboard,, security alarm ...