Intercom allows two additional crew members, for a total of four, to transmit over the radio. This modular system accommodates up to three radios, ten firefighters and fourteen positions, including six intercom positions. Plug and play components and the fewest components of any leading system make the system 900E easy to install, saving time and money. Repairable parts decrease the lifetime cost of ownership, and fast repair turnaround decreases downtime. Radio transmit headsets can be used with a portable radio using an adapter cable (PRAC).