Tapered hole major diameter is 3.500 inches , flow direction is from the outside in; cylindrical shape
NSN 6685-00-832-8769
NSN 5910-01-141-6667
NSN 6620-01-084-2255
NSN 5999-01-048-6369
NSN 6135-01-412-0404
NSN 6130-00-092-1282
NSN 6150-00-995-6589
NSN 6650-01-225-0176
NSN 5960-01-142-1995
NSN 5945-01-428-9544
NSN 5998-01-472-2520
NSN 5999-01-487-0137