A deep winter cycling cap designed to provide under-the-helmet warmth thanks to the cold-stopping comfort of Alpha(R) fabrics from Polartec(R). Breathability - To avoid excess sweat, the technical Polartec(R) fabrics provide warmth and breathability. Fit - The Odyssey Alpha(R) Cap stretches to accommodate most head sizes--and fits beneath any helmet. Temperature - Perfect for deep winter rides, the Odyssey Alpha(R) Cap is powered by the performance of Polartec(R). Thermo - The Odyssey Alpha(R) Cap is the warmest, most-insulated option in our long-distance collection. Windproofness - For top-down warmth, the Odyssey Alpha(R) Cap blocks strong winds on fast descents.