Designed with four-way stretch TNF™ Apex Aerobic fabric, this high-performance, slightly stretchy material thrives in highly aerobic, demanding conditions. Brushed waistband lining doesn't abrade skin, and an internal adjustable clip belt lets you adjust for a precise, secure fit. Ideal for mountaineering and backcountry excursions, this pant (rated at 10 CFM) drastically reduces the effects of windchill and enhances the user's warmth.