The Absolute Zero is Mountain Hardwear's most advanced climbing parka for big mountain guides and alpinists ascending the highest peaks in harsh conditions. We like that its 800-fill down insulation is some of the loftiest, most compressible insulation available, and Mountain Hardwear worked with Allied Down to ensure responsible sourcing and processing. The Pertex Diamond Fuse shell excels at abrasion and water resistance, and welded baffles bolster the parka's overall waterproofing.