stalled a GTE/Magnavox C-2000 Digital Airborne Telephone System consisting of: 1 Ea. Air Radio Telecommunications Unit (ARTU), P/N 724855-801 1 Ea. ARTU Rack, P/N 724868-802 1 Ea. Duplexer, P/N 620317-1 3 Ea. Cabin Data Bus Repeater (CDBR-1), P/N 724864-801 '1 Ea. Cabin Data Bus Repeater (CDBR-2),'P/N 9