OROS Solarcore Explorer 1/4 Zip Wind Resistant Pullover- Size Large Insulated with Solarcore-a material inspired by NASA space shuttles insulation for -455° F temperatures Shell made from polyester with four-way stretch built-in for maximum range of motion Highly wind-resistant and slightly water-resistant Super breathable to handle changing weather forecasts and performance needs Insulated throughout the core to maximize weight and packability Thumb holes.