Lightweight warmth, temperature regulating airflow, performance stretch – the Proton Pant is all-mountain versatile. Wear it as a midlayer in cold conditions, or pull it on as a standalone for hikes and approaches. Ultralight Octa® Loft knit insulation combines warmth and breathability, air-permeable Fortius™ Air 50 outer is light, durable, and stretchy, and a DWR treatment repels moisture. The trim fit layers easily, and articulated patterning works with the stretch to remove restriction.