Wireless GSM Alarm System: 16 wireless ,3 wired zone 5 groups of ... adopt two frequency,four frequency GSM / GPRS industry modules, stabilityreliably, the whole world all can use.2, Support GSM / CDMA mobile phones, compatible middle ... : FSK, to receive from 100-250 meters. 4, alarm mode: GSM network alarm, SMS alarm. 5, stored telephone numbers: 5 groups ...