Castelli viva thermo headband the castelli thermo headband is for slightly warmer days when you still want some protection for your ears but want to feel a little airflow over your head or use as a headband to absorb sweat the seamless design adds to comfort features thermoflex is warm soft and stretchy raw cut edge lies flat and doesnt bunch up uni size one size fits all buy castelli clothing at chain reaction cycles the worlds largest online bike store