What Our Gearhead(R) Experts Are Saying:"I wore this under my helmet on a windy, cold morning ride, and my ears never went numb once, which almost never happens. The front panel really does block wind better than any cap I've used before. This is the first thing I grab when the forecast looks harsh."Wind finds the gaps first, sneaking in around the ears and across the forehead until the ride stops being fun and starts being an endurance test. The Castelli Estremo Thermal Winter Cap closes those gaps before they become a problem. Polartec AirCore fabric across the front cuts wind on contact, while a full ear cover keeps the cold from creeping in from the sides. A warmer, breathable fabric on the back balances things out, so heat doesn't build up under the helmet even as the front stays sealed against the elements. It's a small piece that makes a big difference on the days when everyone else is still deciding whether to ride at all.