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 5910-01-365-2129
NSN 6135-01-400-2947
NSN 5915-00-982-7941
NSN 2925-01-535-7235
NSN 5985-01-450-2186
NSN 6650-00-226-7099
NSN 4140-01-226-3314
NSN 6130-00-281-5978
NSN 5835-00-286-5432
NSN 5975-00-678-5233
NSN 6105-01-606-1209
NSN 6150-00-523-6707