PurposeUSED FOR TROUBLESHOOTING THE AIRPLANE SYSTEM WIRING WHICH INTERFACES WITH ARINC 404 TYPE RACK CONNECTORS, TYPICALLY THOSE WITH ARINC B SHELLS AND WHERE THE ASSOCIATED LRU HAS A CORRESPONDING CONNECTOR (ARINC B SHELL STYLE) MOUNTED VERTICALLY ALONG ITS CENTAirplane737, 747, 757, 767, 777-200, 777-200ER, 777-200LR, 777-300, 777-300ER, 777-8, 777-9, 777FUsage CodeMAINTENANCE 