The Ultra Tight is designed for cool weather endurance running. Our proprietary back pocket system keeps two gel flasks securely in place to fuel you through those extra long runs, climbs and summits. Soft interior and waterproof calf and ankle panels will keep you warm and dry. Thermal Lite fabric provides superior moisture transfer and warmth. Softshell Lite fabric ankle and calf splash panel features a breathable, waterproof laminate. Two angled back 3 oz. gel flask pockets patent pending. One zippered back pocket.