The Castelli Estremo WS Cycling Cap is designed to keep your head warm in the worst conditions, without causing it to overheat.
The GORE-TEX® fabric at the front is fleece-lined for added softness, while being totally windproof and water resistant. It will therefore keep your head comfortable and protected, while the Warmer fabric at the back of the hat is more breathable, with no windproof veneer, so will allow moisture to escape freely. A drop-down earflap will shield your ears from the wind as you cycle.