UP FOR AUCTION IS AN AM 503 CURRENT PROBE AMPLIFIER WITH A TM 501 POWER MODULE. THE UNIT HAS BEEN PLUGGED IN AND POWERS ON AND OFF PERFECTLY. THE UNIT SHOWS JUST A LITTLE VERY MINOR WEAR AND SCRATCHES HERE AND THERE, BUT NOTHING AT ALL SERIOUS. OVERALL, IT APPEARS TO BE IN GREAT CONDITION. AWESOME AND VERY RARE. THANKS FOR LOOKING.