Ciele doesn't make products that we would ever tell you not to run in. In this case, however, we're asking you not to run in ACBeanie. Why? Good question.

The ACBeanie is a thicker (twice as thick), heavier (twice as heavy) version of Ciele's other merino wool beanies. Yes, the combination of merino and silk regulates temperature incredibly well. Yes, the airBEAM™ ventilation still lets some heat out, but the weight of this exclusive knit beanie means it's strictly a great everyday beanie.

90% wool, 10% silk.