The Arc'teryx Proton Pant is designed to meet the dynamic needs of mountain pursuits and perform as a self-regulating midlayer or a stand alone pant for a variety of alpine activities. Air permeable Fortius™ Air 40 fabric gives weather resistance for protection in alpine environments. Octa® Loft, clean finished, breathable insulation provides thermal protection while maintaining a comfortable micro climate. An elasticized waistband gives stretch and a precise fit. A zippered thigh pocket stores small items.