The castelli viva thermo headband is the perfect between season accessory this headband is ideal for those days when you want to keep the chill off your ears but have maximum air flow through your helmet vents those in between days where you have to deal with freezing ears for a little helmet ventilation are over the viva thermo is crafted from a thermoflex material which is warm soft stretchy and incredibly comfortable this material is also moisture wicking and so keeps you dry and comfo