Tapered hole major diameter is 3.500 inches , flow direction is from the outside in; cylindrical shape
NSN 5905-00-107-5533
NSN 4140-00-488-9468
NSN 6105-01-555-8995
NSN 6130-00-418-2266
NSN 6135-01-308-5688
NSN 6110-00-686-4685
NSN 6130-01-272-3117
NSN 6145-01-510-9825
NSN 5915-00-152-4016
NSN 7035-01-080-8742
NSN 5975-01-196-3502
NSN 6135-00-416-2898