Ever a popular item: the USMC reversible poncho liner with zipper.
Brand new straight from the carton, these are completely unused.
Size wise, this is a funky shape so its hard to describe. But its a little over 7 feet long and a little over 5'6" when opened fully. It has tie points at the corners and half way between those to tie into a poncho. the zipper makes it the equivalent of an extra long sleeping bag.