1/4-19 thread size; 20.6 m o.D.; 13.7 mm i.D.; 2.0 mm width; used on k4 style straight fittings as a port seal
NSN 5910-00-081-9046
NSN 6130-01-333-1895
NSN 4140-01-224-7662
NSN 5998-01-139-4114
NSN 4140-01-083-1919
NSN 6135-01-128-5358
NSN 6240-01-188-7282
NSN 5925-00-830-4896
NSN 6220-01-414-0623
NSN 6135-00-935-2589
NSN 5935-01-422-3228
NSN 5855-00-688-9954