Technical parameter for coding intercom system Working voltage:DC10.8V~16V Audio frequency not distorted output: The main channel: 5mw min Reply channel: 100mw min Frequency response:300~3400HZ?db Environment temperature :-40 to+70 Humidity:45% to 95% Working current of camera:500mA?0mA Camera:1/3' CCD Definition:380 TV Lines