2 channel master station with built in power supply (2A), 1RU - The PS279 is a 2-channel intercom station with a built-in power supply, housed in a 19"/1U metal case. It provides all the features necessary for a two channel communication system, in conjunction with the PRO Series beltpacks and speaker stations. FEATURES Power Supply Section The built-in power supply drives 20 beltpacks or 10 dual channel speaker stations, or a combination of the two. DC Input TALK and CALL Functions Volume Control Mic Mute Push Button Binaural Headset Connector (optional) Buzzer Mute AUX / Program Input System Link Ground Lift on AUX Input