Excellent thermal mid layer for aerobic activities or expedition weight insulation for cold winter sports. Form fitting versions feature Polartec® Power Stretch®, which wicks moisture and prevents constriction. Thermally efficient zip neck foundation piece suited to cold temperatures, slower paced activities. Plush interior has rich, warm texture. Trim, next-to-body fit and elastane content increases thermal efficiency by keeping fabric in constant contact with the body. Zip neck opens to aid rapid temperature regulation.