This "one-size-fits-all," tightly-woven acrylic hat is essentially a high-quality beanie with a brim sewn in. The brim must be for fashion, because it is far too small to be useful. The lower half of the cap folds upward to approximately half of the cap's height, so that two layers of fabric surround one's head. This double-layer of tightly-woven fabric is what gives the cap its substantial warmth, and wind-breaking ability. It is the warmest single piece of head-wear I own. Considering its warmth, price, and quality of construction, I believe this hat clearly deserves a 5 star rating. In addition, it is proudly made in the U.S.A.

BTW, my tip for staying warm in frigid weather is to wear a turtleneck sweater, and to then wrap a warm scarf around your neck (I use a green wool scarf from my Army days). When both your head and neck are warm and the wind cannot blow down your coat's collar, three-quarters of the battle to stay warm is won.