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 6620-01-417-3314
NSN 6220-01-083-5822
NSN 5935-00-309-7963
NSN 5996-01-227-2555
NSN 5999-00-021-9540
NSN 6645-01-439-4240
NSN 6620-00-430-5727
NSN 6645-01-204-7094
NSN 6650-01-533-1267
NSN 5855-00-167-7893
NSN 5960-00-491-6580
NSN 5905-01-466-0337