... ,Transfer rate:250K wireless voice door phone for long distance 500m 1V31,2.4G ISM Public Frequency Band ... 20dBm(100mw)4,AFH Adaptive Frequency Hopping technology, with wireless LAN and Bluetooth devices share 2.4G ... then the CALL button, enter the main CALL with the red lightB:No response signal 4 seconds ... enter the call state with the green light. C:Indoor monitor keep a long red light and ring when ...