Picked up two sets of these in a pile of ACU trousers. I've handled quite a few ACUs over the last few years and have never seen these before. What are they? My initial thought as I was quickly sorting through the pile is I had picked up some Goretex trousers. Closer examination led me to believe it was part of a layered/level ECWS type of kit. Aviation? Cold weather over trouser? The NSN and contractor number seem legit when I looked them up. They feel like regular ACU material to the touch. Doesn't seem to be anything different material wise.
What are these? Are they significant? Collectible? Rare? Not rare? Any value? Someone enlighten me please!? Thanks.