Home Alarm System 1,Touch keypad,Big LCD display 2,GSM+PSTN dual network 3,8 wired + 30 wireless zones 4,Work ... Touch keypad; Big LCD displays 2. GSM+PSTN dual network. If PSTN is disable, it will switch to GSM ... 1AC/DC Adaptor*1User manual*1 FAQ of GSM Security System:1: About GSM frequency: it can support 850/ ... info,pls connect with us freely......... GSM+PSTN Dual-network Home Alarm System