Use the 4ATRU to add four loop start trunks to your NEC DS2000 phone system. The 4ATRU PCB has a Mode Switch, a status LED indicating proper PCB operation, and a port activity LED that indicates traffic on the PCB. You can install 2 4ATRU PCBs in a Fixed Slot 4-Slot Cabinet, and up to 3 4ATRU PCBs in a Universal Slot 4-Slot Cabinet. The number you can install in an 8-Slot Cabinet depends on system configuration.

Each 4ATRU PCB also provides 2 power failure cut-through circuits. When commercial AC power fails, the PCB automatically cuts through 2 trunk circuits to 2 power failure telephones.

"B" Version required for built-in Caller ID.