Nice and simple design, stylish looking and not bulky. No need to press any buttons to talk simply talk to the person on the opposite side. * Master station is fully hands-free * Master station powers substation * Rotary switched volume control for master station * Master station can control voulme for substation and master * Supplied with interconnection cable and AC/DC adaptor * REC output connection(to record conversation using any recorder) * Extension output( you can have a extra mic) SPECIFICATION: Power supply 12Vdc, 300mA Consumption 300mA Output power: 4W + 1W, 100Hz - 15kHz Microphone: -61dB±0.5dB, 20Hz - 16kHz