The Men's Formula Pants give you the freedom needed to make efficient moves on challenging runs. Legs stay warm and dry thanks to KJUS FAST Thermo Core™ insulation, which intelligently regulates body temperature, and Toray Dermizax™ shell fabric which is light, soft and 1% waterproof. These pants are incredibly stretchy, with four-way-stretch materials from the shell, through the insulation and down to the lining. They have a new, engineered waistband and modern, international fit in the groin for comfort, and we've improved the waist-adjustment system for better control over the fit. If you expect your pants to work as hard as you do, then these are for you.