The ultra-warm carefully crafted high-altitude climbing pants alpinists depend on. The Absolute Zero Pant now uses 800-fill RDS-Certified, fluorine-free Allied Downthe most responsibly-sourced and -processed down insulation available. We worked with Garrett Madison, big mountain guide and Mountain Hardwear elite athlete, to ensure that the evolution of this welded, waterproof construction continues to withstand the harshest conditions atop the worlds highest peaks.