Assos Thermobooster Foil Black Series, One Size

What Our Gearhead(R) Experts Are Saying: "I always keep the ThermoBooster Foil tucked in my jersey pocket. It's super light, blocks wind and water, and adds instant warmth when the weather turns cold on descents. Total lifesaver for big mountain days."We've traded newspaper hacks for technical precision. The Assos ThermoBooster Foil delivers featherweight, packable defense against cold wind and wet conditions, ideal for descents that drop temps fast. It's one of those pieces we hardly notice until the moment we need it most. Designed for winter training and year-round preparedness, this ultralight shield packs into a jersey pocket but offers heavyweight performance when deployed. Its windproof and waterproof construction wraps us in instant warmth and protection without adding bulk. Whether we're dropping alpine passes or coasting into town under a gray sky, this is the layer we rely on for backup comfort in unpredictable conditions.