Best Use: Active Cold ConditionsToray's 3DeFX+® insulation has opened the door for an entirely new type of highly breathable insulation for active use, which is perfect for cold weather mountain hunting applications. The 3DeFX+® synthetic insulation is the first of its kind to incorporate continuous fiber technology. The long spiral strands of fill are loftier and warmer than any other synthetic insulation on the market.The Kenai Hat features 70 x 80D Stunner Stretch nylon face fabric that's extremely durable, strong, and coated to make it windproof and water resistant. A high loft Sherpa fleece lining makes the interior incredibly warm and comfortable. Heavily insulated, windproof, and with ear flaps to really lock in the heat, the Kenai Hat is a must have for the coldest late season conditions.