The US Marine Corps P-44 Shirt/Jacket was one of the latter iterations of the lightweight combat uniforms issued from 1944, and mainly seen in use across the Pacific field of conflict. Made from a 8.2oz herringbone twill, or HBT was initially meant to be worn over the standard-issue uniform for protection against general wear whilst doing fatigue duties, but it was quickly adopted as the uniform of choice in hotter climates due to it's light weight and durable fabric.
The two symmetrical chest pockets were initially designed to contain two personal floatation 'bladders' which were inflated for amphibious landing to help keep the soldier afloat, though were much more commonly used as large storage pockets, making this jacket incredibly practical. Post WWII these surplus jackets were adopted by hippies and outdoors people alike, for their rugged durability and easy aesthetic.
Constructed from soft Portuguese cotton Herringbone Twill