The Telex BP-351 Dual-Channel Portable Metal Beltpack with 5-pin Connector (Black) is a portable microprocessor-controlled intercom beltpack designed to work with Telex RTS two-wire intercom systems. The device has a 5-pin XLR connection for a headset/earset microphone (dynamic/electret), a 3-pin XLR female connector for intercom line and power, and an XLR male loop-through connection for connecting multiple beltpacks together in a chain.
For controls, the unit features a rotary volume control, a channel select button for switching between channels 1 and 2, a call button with indicator light for sending and receiving call signals and a talk button with indicator light. You can talk on the intercom in latched mode where you tap the talk button once to talk and again to turn it off or in momentary mode where the button must be pressed while you talk. The system also includes a sidetone control for adjusting the level of your own voice within your earset.