For cool to cold days, the addition of a Gore Windstopper base layer to your normal clothing set up will keep you warmer without adding bulky layers. Keeping sweat off your skin will keep you cool on the way up & prevent wind chill on the way down. Key Features:Gore Windstopper Technology: windproof, water resistant, highly breathable,Gore Windstopper insert on front, over ,Reflective logo on front,Minimized seams,Flat-lock seams,Great moisture management,Quick dry,Next-to-skin comfort.