2-Channel Headset/Speaker Main Station with built-in 2-amp power supply, rack mount (1RU) - UL Listed Compact, feature-laden, single rack-space intercom main station supports up to 40 RS-701 beltpacks, 10 speaker stations or 12 headset stations on two channels. Other features include: - Channel A-B linking - Program input with individual channel level controls - Remote Mic Kill switch - External relay circuit - Stage Announce