... conversation broadcasting call for help IP network emergency call box for emergency call Enabled by TCP/IP technology, Huanyutong ... , can work with active speaker.• Short-circuit output and input interfaces, can receive and control some peripheral devices.• Works ... /3color camera(optional)InterfaceAudio output, 4 short-circuit input, 2 short-circuit output, SD card holder, RJ45Dimensions310x420x140mm