RemoteMix 4 is a four channel field mixer combined with a four channel headphone amplifier. Includes a phone line hybrid and keypad, as well as a universal PBX handset interface and a 2.5 mm wireless phone interface. It can also connect to cell phones and portables using Bluetooth Wireless Technology. All this in a tough, portable unit that’s smaller than a lunch box. All-in-one is an understatement. These parts were designed to work together and save setup time in the field. No need to send an engineer with patch cables. All the pieces work together in one reliable unit.RemoteMix 4 now features HD Voice technology, allowing 7 kHz Wide Band Speech when used with compatible phones on compatible networks.