... the use of industrial GSM / GPRS communication module 850/900/1800/1900MHZ options, global coverage.2, IMEI code query, set the ... host using learning style of the code, simple and convenient. 20, single-zone deployment mode. 7 Way wired zones alarm inputs, 2 ... field, and so on, wired telephone networks can not reach. GSM security alarm system with LED display and keyboard,, security alarm system