Federal Signal's AudioMaster® 310-MV is an industrial intercom that provides reliable two-way communications and superior sound quality.The AudioMaster 310-MV's standard features include volume control, call button, balanced line output, dust- and water-tight housing, listen/talk switch, remote device activation and the ability to power another intercom at 24VDC.This heavy duty intercom will operate from -31°F to 150°F (-35°C to 66°C) in both indoor and outdoor applications. Remote device activation allows you to activate an auxiliary signal such as a horn or light.The AudioMaster 310-MV intercom is easy to operate. Press the toggle switch to talk and then release to listen. Additionally, press the call button to get the attention of personnel at another intercom.The 310-MV is ideal for use at oil refineries, petrochemical plants, offshore platforms, pulp and paper mills, water treatment facilities, airports, shipyards or anywhere reliable two-way communication is important for safe and efficient operation.