Washer is 12 mm for the oil pan drain plug
No other part numbers with same form, fit, and function found.
NSN 5835-01-495-5986
NSN 5990-01-449-7090
NSN 6650-00-522-5795
NSN 5996-01-654-3472
NSN 5960-00-656-2451
NSN 6620-00-663-8449
NSN 6645-01-174-0859
NSN 5998-01-276-9428
NSN 6240-00-793-7969
NSN 5905-01-524-3132
NSN 5935-01-154-4660
NSN 5945-00-753-5127