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 6150-00-864-8125
NSN 5975-00-380-5753
NSN 6685-01-469-3025
NSN 5925-01-099-9542
NSN 5996-01-472-2761
NSN 5985-01-428-3820
NSN 5930-01-343-6660
NSN 6240-01-462-5433
NSN 6645-00-527-6531
NSN 5925-01-459-2249
NSN 4140-01-431-2317
NSN 6105-00-546-5148