... 1, PSTN & GSM security alarm with LED display and keyboard 2,99 wireless and 2 wired 3,Voice prompt function 1, PSTN & GSM, Voice prompt ... scene location information answer. 13, when the wireless linkage device with alarm, convenient linkage power, lights, video and so on. 14, ... field, and so on, wired telephone networks can not reach. GSM security alarm system with LED display and keyboard,, security ...