Arc'teryx Rho AR Zip Neck - Women's: Breathable, moisture-wicking, insulated jersey with collar zip to aid with temperature regulation Excellent thermal mid layer for aerobic activities or expedition weight insulation for cold winter sports. Form fitting versions feature PolartecA(R) Power StretchA(R), 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. Features: RHO - Thermally efficient base layer with excellent moisture management properties. Has stretch comfort. ALL ROUND - High performance weather protection and materials, emphasizing versatility for multiple activities. ARC'TERYX ESSENTIALS - Versatile high performance designs for diverse activities and conditions. POLARTECA(R) - Synthetic fleece textiles with stretch, warmth and air permeable properties. Offers durability.