The ATUC-IRDU has a 3-pin XLRF-type input for use with ATUC-M43H, ATUC-M58H and ATUC-M32L microphones. Configured for up to two users, the unit includes dual request-to-talk/mute buttons, indicator LEDs, and 3.5 mm (1/8") headphone jacks with volume controls, giving both users equal access to the microphone. The IRDU is also equipped with a channel/volume display, channel selection buttons, and built-in speaker. It is designed for tabletop or recessed mounting, and is powered by one or two LI-240 lithium batteries (available separately) for approximately 6.5 or 13 hours of use, or by an AC adapter (available separately).