IHM-35-KHA Whipcord N1 Deck Jacket - KhakiIHM 35 KHA The classic N1 deck jacket was first produced for the US Navy in the early 1940s. Much copied since then, it has become a true style icon in its own right. The Iron Heart version remains pretty true to the original jackets on the basis that "if it ain't broke, don't fix it". Theyve made a minor tweak to the pocket placement to increase functionality, but the one major upgrade they made goes unnoticed the addition of an interlining inside