5640-00-521-6863 (A-A-2243)
5640-00-521-6863 is equivalent to manufacture part number 801. It is a vege hard pressed building board and is classified under Federal Supply Class 5640 (5640 - Wallboard and Insulation), stocked for defense, aerospace, MRO, and industrial maintenance applications. This item is cataloged in the NATO supply system under 5640 - Wallboard and Insulation and is available through NSN-PARTS for U.S. government MRO, and commercial procurement.