This bivvy sack that doubles as a parka was developed as a Swedish Air Force survival kit item. When you put it on, it looks like a hooded nightshirt. During the day, you roll up the drawstring hem and wear it as an anorak. At night, there's enough room inside for your sleeping bag and it can also act as a small, emergency tent (the cuffs are elastic drawstring, too). A bit pricey, but worth it. Mine kept me dry and fairly comfy when I spent some time last winter camping out in Oregon in the cold, blowing rain (temp.: 40s). It's great for pier fishing and crabbing in the rain, too. Folded up, it's about half the size of a loaf of bread and weighs about a pound. There's no lining; it's just a generic shell (I also wore mine in conjunction with a mummy bag). It breathes pretty well, though, and seems pretty resistant to tears and punctures.