This is a GI Style 5 Quart Flotation Bladder Canteen. It is collapsible and has an olive drab nylon carrier. The 5 quart canteen was fielded in Vietnam in 1968. It was made of all soft materials so that as water was withdrawn, it would collapse and hold the remaining water without sloshing sounds. This requirement to be tactically quiet was one of the main objectives for the 5-quart canteen. The OD106 nylon cover has nylon tape loops and string ties sewn in at each corner, making it easy to secure the 5-quart canteen to a rucksack, packboard, vehicle or other attachment point. A snap opening at the side is provided to insert or remove the bladder. The Cover also has Printed Instructions on the outside. A folding fabric funnel at the top is used when filling the canteen. A pocket for water purification tablets (with velcro closure) was available on the outside of the cover. In addition to its use as a 5-quart canteen, the design anticipated its use as a flotation bladder that would support the weight of a soldier and his equipment. It could also be used as a pillow.