I rather suspect that the bag in the original post is the Thatchreed version.
They make copies of British Army kit aimed a Kay-dets, airsofters and skint squaddies. You may also find they make some pretty outlandish sizes which can attract the, shall we say, less petite outdoors person.
Personally, the only thing I can say about it all concerns bargepoles although I own one of their windproof smocks - a present.