6685-00-135-4723 (670M1043)
6685-00-135-4723 is equivalent to manufacture part number 3-54709. It is a recording pyrometer and is classified under Federal Supply Class 6685 (6685 - Pressure, Temperature, and Humidity Instruments), stocked for defense, aerospace, MRO, and industrial maintenance applications. This item is cataloged in the NATO supply system under 6685 - Pressure, Temperature, and Humidity Instruments and is available through NSN-PARTS for U.S. government MRO, and commercial procurement.