Made from Castelli's thermoflex fabric that is soft, warm and stretchy - to bring a little coziness under the lid on those cooler rides. The raw cut edge lies flat against the skin and will not bunch up when you put on your helmet. Wear it above or over the ears.
The Garmin Cervelo Pro cycling team uses the Viva Thermo headband and Viva Thermo Skully on their Fall/Winter training rides.