The US Navy adopted the N-3 utility jacket in the early 1940s. The simple specifications with one patch pocket on the chest and two patch pockets on the waist have almost the same appearance as the P-41 adopted by the US Marine Corps at the same time. Identify by "USN" or "USMC" marked on the chest pocket. The button is a black-painted donut-shaped tuck button used during the war and is engraved with laurel. The sleeve is a single tubular sleeve, and can be adjusted with two tuck buttons driven into the sleeve tip. When World War II broke out and the number of soldiers increased, additional production of equipment was urgently needed, and a jacket that was simplified to the utmost limit like this N-3 was a very suitable jacket for mass production.