The N1 deck jacket was first issued to US Navy servicemen in the early 1940s. Much copied in the years since, this military classic has evolved to become a true style icon in its own right. The Iron Heart take on the N1 remains pretty true to those original jackets—“if it ain't broke, don't fix it”—constructed with a highly durable whipcord outer shell and a high-density lining blended from sheep and alpaca wool. Of course, we’ve also given the original design a few innovative upgrades, most notably a hidden chino interlining to enhance wind resistance and a heavy-duty two-way zipper concealed beneath the traditional buttoned storm placket. This creates a formidable winter jacket, seamlessly blending authentic WW2-era styling with modern performance and functionality.