This US military rain poncho liner is also known as Woobie, because "without one, you woobie cold!" A very nice, lightweight, rather warm, and super cheap blanket & thermal cloak that has more uses than you'd think thanks to the tiestrings everywhere. Use it in the wood, at home, or keep it in your car if you run out of gas or your battery dies.
First used in the Vietnam War, the lightweight rain poncho liner was designed as a replacement for the wool blanket. It was tied up with the rain poncho to make a light sleeping bag. In comparison to the wool blanket, it is a lot lighter and a bit warmer. It also dries faster and can be packed into a very small space. Not only praised by the Vietnam War veterans but veterans of more modern conflicts as well - this thing is still very much in use.
If you want to see more praise and interesting tidbits of information, go and read this educational and entertaining Task & Purpose article.
The rain poncho liner is warmer than the US military blanket. Since it is made from synthetic materials, it is also very lightweight, packable, and quick to dry. When compressed with general-purpose straps, the rain poncho & liner combo turns into a bundle that is a bit smaller than a football (the European kind). With a modern compression bag, you can go even smaller. Available in the versatile Woodland camo pattern.
US military surplus. These are all used but in perfectly serviceable condition. There are older and newer Woobies in this batch, and in the older ones, the colors can be a bit faded. We sometimes have these in unissued condition, too, in case you don't like used ones.