When you want a warm, sleek, breathable jacket for running day or night in cool conditions, the Women's Quantum Long Sleeve Zip Hoodie delivers maximum comfort and mobility. Crafted for movement with raglan sleeves and underarm gussets, the Quantum Hoodie also has breathable eyelet mesh panels for comfort when you generate maximum energy. Reflective details aid visibility for running at night, and a fitted hood adds warmth when you need it without added fabric. And the warm, midweight 260gm merino terry also makes Quantum a great midlayer for ski touring, climbing in the mountains, or any active sport in cool to cold weather. And with merino's natural odor resistance, you can wear it day after day, sport after sport, between washings.