Mountain Hardwear Phantom 0 GORE-TEX Windstopper 850 Down Sleeping Bag - The Mountain Hardwear Phantom 0 GORE-TEX Windstopper 850 Down Sleeping Bag is constructed with GORE-TEX WindStopper fabric. With a center zip, the Phantom is breathable, highly water-resistant, and windproof. Insulated with goose down for optimal warmth-to-weight ratio and compressibility.