The Studio-Tech Model 37 Intercom Beltpack is a self-contained unit designed for use by on-air, production, or engineering personnel. Directly compatible with 4-wire matrix intercom systems or standard analog audio circuits. Supports single- and dual-muff headsets that utilize dynamic microphones. Interfaces using standard 4-pair RJ45 cables. Requires a source of 10-18 Vdc for operation. Includes power entry and aux audio input modules.