Quality reproduction of the M1928 Haversack- the standard issue backpack for US soldiers until the end of WWII. These are a slightly modified version of the M1910 Haversack used in the First World War (which were also used in the Second).
This pack was designed specifically to fold around the soldier's kit (hygiene items, spare clothing, etc), with a separate pouch for the mess kit and utensils. Two pairs of eyelets permit one to attach the shovel carrier and bayonet to the outside. A pack carrier or "tail" could be attached to the bottom, lengthening the pack to allow the bedroll to be carried if desired.