The timeless thermal benefits and all weather durability of wool never go out of style, and neither will the Big Sky. This Merrell Aeroblock™ pullover blocks chilling winds with its wool blend exterior, and combines with a warm fleece backing to create the ultimate single layer jacket. Merrell Aeroblock™ provides high wind-resistance and breathability. 62% polyester / 27% wool / 11% nylon. 12 CFM Wool blend fabric with fleece backing. Comfort ribbed interior collar. Comfort ribbing under arm for ease of movement. Drawcord adjustable hem. Two zippered hand pockets.