Black Diamond Twilight Bivy is an ultralight and highly packable bivy for backcountry minimalists. It weighs in at a mere 10 ounces and is highly water-resistant yet extremely breathable.
Black Diamond Twilight Bivy is made with NanoShield fabric, a new proprietary breathable single-layer fabric. NanoShield is extremely water resistant: it has the highest water column rating of any breathable single-layer, single-wall fabric at 1700mm. Such as outstanding rating is the result of BD's exclusive Silicone Nanocell coating. This coating has a much lower volume than typical water-resistant coatings, allowing the fabric to remain superlight, soft and packable.
Despite its thin profile, Silicone Nanocell is highly durable with impressive tear strength, making it perfect for high winds and abrasion resistance when guying-out to nearby rocks, ice or trees. It loses nothing in breathability to less weatherproof fabrics, boasting a Moisture Vapor Transmission Rate (MVTR) of 4300.