The Sea To Summit Trek Sleeping Bag is specifically designed for women, keeping us warm and cozy during chilly weather car camping adventures. The semi-rectangular shape offers more room around the shoulders and hips, and a half-length side zipper and footbox zipper, in addition to the main, full-length zipper, give us plenty of options for ventilation. The 650-fill duck down is treated with a hydrophobic Ultra Dry Down treatment to keep us warm in damp conditions, and the baffles change direction midway down the bag to increase heat retention.