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When the temperature dips, don our comfortable women's REI Activestretch beanie for warmth whether you're running, skiing or walking the dog. Polyester/nylon/spandex fabric blend provides 4-way stretch and dries fast, making it ideal for skiing, cold-weather cycling and other active sports. With a UPF 50+ rating, fabric provides excellent protection against harmful ultraviolet rays. Ponytail opening in back manages your hair while wearing the hat. Reflective detailing front and back increases your visibility in low light. 1 size fits most.