... battery;Standby current: 6.5mA;Operating current: 70mA.8,Communication distance: 500 meters for barrier free Details:Wireless intercom ... 2.4G Communications Channel, full-duplex interoperability intercom, communication distance up to 500 meters aboveInstructions:1,Boot:Connect the power or ... prompted no signal, ends CALL state. Signal received, began to sound a beep tone: A,If no answer, stop beep ...