... . AC 110/220V,or Li-ion battery power supply,Standby Current: 6.5Ma, Operation current:70mA.8 ... 300 meters in open landOperationuPower onConnect the plug to electricity.uStandby statusHand up status: the intercom always ... Press the ID number of the intercom you want to call, then press CALL button, RED light bright ... 0~99, press the ID number which you want to set, then confirm by pressing CALL key, then ...