Great Ultralight Bivy
I use this bivy for backpacking and car camping. It is extremely compact if compressed a little it's a little bigger than a baseball, light, and breathable. It's not entirely waterproof but will keep you dry from light rain and morning dew, it does a good job keeping the wind off as well. I usually pair it with a light weight tarp in heavier rain and snow. It's pretty spacious, I'm 5'8, 165lbs and I have tons of space to move around and enough room for my boots and clothes if needed. There are loops that you can easily tie up the cloth around the face area to keep it elevated but the material is so light I barely notice it when I sleep. Over this is an awesome bivy.