The Sierra Designs Backcountry Bivy is a four season bivy for solo backpackers looking to go lightweight. The 30D nylon ripstop floor is waterproof and durable for setting up camp without having to worry too much about damage. The two zippers at the front Are your doors, the larger of the two can be left wide open, accommodating the comforter-style backcountry bed better. If it's buggy out but still warm, close the main zipper and open up the mesh window for a bit of star gazing. If bad weather arrives, close completely for waterproof protection through the night. Features of the Sierra Designs Backcountry Bivy BCB compatibility Waterproof and Breathable Ventilation