What Our Gearhead(R) Experts Are Saying:"I wore this on a long alpine push, and it fit easily under my helmet without any bunching. The moisture-wicking fabric kept my head from overheating on the steep sections, then held its warmth once I stopped to rest."Big mountain days bring big temperature swings, and Mammut built the Taiss Beanie to keep pace with every one of them. The recycled polyester spandex blend wicks away moisture on a steep, sweaty pitch, then holds warmth the moment you stop to catch your breath, all in a lightweight, stretchy fit that layers easily under a helmet.