... , LCD display, with keypad to operate, very easy to operate2, GSM network, no need telephone line3, Know which zone triggers from ... support all kinds of wireless sensors, such as PIR detectors, door (gap) sensors, gas sensors, smoke sensors, beams, panic buttons and ... , when power is on, will also alertTechnical parameter for the gsm alarm system wireless:Operating voltage: Input 100-250V, output 12V ...