You may not be able to stop all the crazy stuff that comes out of your mouth sometimes, but at least you can keep your body heat from escaping through your head. Keep your dome warm with the Patagonia Lined Beanie. Cozy merino wool blend fabric. Fully lined with a moisture-wicking fleece. Fits under a helmet or hood. Shell: 51% acrylic, 49% merino wool. Lining: 100% polyester. Hand wash cold and dry flat. Imported. Measurements: ; Circumference: 22 in ; Product measurements were taken using size One Size (21 1/2-23 1/2). Please note that measurements may vary by size.