EAR COVERAGE: Designed for full ear coverage to maximize warmth and minimize heat loss. HELMET COMPATIBLE: Snug design for use under a hood or helmet for a seamless fit so it fills a gap in your kit without complicating the rest of the system. LIGHTWEIGHT: Travel-friendly and so light you’ll hardly notice it’s there. SLEEK DESIGN: Simple and effective, the redesigned low profile dome shape is perfect for keeping you warm. WIND-RESISTANT: Polartec Windbloc fabric blocks 100% of wind offering maximum protection from the cold and the elements.