... , LCD display, with keypad to operate, very easy to operate2, GSM network, no need telephone line3, Know which zone triggers from ... , when power is on, will also alertTechnical parameter for the gsm alarm system wireless:Operating voltage: Input 100-250V, output 12V ... Frequency: 433 MHZ, 850/900/1800/1900MHZStandard kits of the gsm alarm system: a main panel, a wireless PIR detector, a ...