Here's what other sites are saying:
If sleeping in a glorified body bag doesn't feel right, you can pitch the weatherproof Integral Designs Nestor Bivy and get the space you desire without carrying the weight of a tent while backpacking or climbing. This tunnel-like bivy keeps the showers off and your claustrophobia at bay, and uses two poles to provide a comfortable 23.6-inch ceiling. A large mesh window and breathable fabric provide ventilation during summer backpacking trips while the long length provides a little room to keep your boots and pack dry during overnight storms.
The Integral Designs Nestor Bivy is perfect for the alpine adventurer who wants the low weight and convenience of a bivy but the comfort and space of a tent.