... stop when you hang off. Audio Control: record according to testing the audio signals, likes intercom, sound ... 6 piecesMax power Consumption7.5WWork Temperature 0°C-50°C SNR(signal noise ratio) ≥30dBHumidity 10 ... %-80%Reservation Temperature -20°C-80°CFrequency Response 300-3400Hz(±3dB)Input Impedance ... Exchange ChannelsDTMF Code 0~9,*,#,A,B,C,DAudio File WAV, VD8,AGC Vibration Tolerance ...