Federal Signal's AudioMaster 310-MV-MNC is a two-way industrial intercom that provides reliable communications and superior sound quality. The AudioMaster 310-MV-MNC's standard features include volume control, call button, balanced line output, listen/talk switch, remote device activation and the ability to power another intercom at 24 VDC. This heavy duty intercom will operate from -31 to 150 deg F. The remote device activation feature allows you to activate an auxiliary signal such as a horn or light. When the ambient noise level is too high for the standard 310-MV integrated microphone, the 310-MV-MNC noise canceling unit is used to improve transmission quality.