These 1NB7-8348 Hybrid IC's for use in the Agilent HP 54845A, HP54845B, 54846A and 54846B have been tested extremely thoroughly. First they were each installed in a known good HP54845A had self calibration and then self test performed. If they passed self calibration and self test we then took the hybrid out of the unit it just passed in, and installed in a different known good HP54845A unit and ran self calibration and self tests again. The parts had to pass in both units all tests before we passed them. These parts are definitely good!