The Mountain Hardwear Ratio Sleeping Bag is lightweight and keeps you consistently warm on backpacking trips from the end of spring to the beginning of fall. ThermoTrap Baffle construction secures 650 fill down insulation in smaller chambers to balance the down evenly across the entire bag, and the down's Q. Shield treatment helps the down resist moisture to retain its heat trapping loft and keep you warm on cold nights. Its comfort mummy cut provides a slightly larger shape than standard mummy bags to keep you comfy without adding weight or reducing warmth. Mountain Hardwear made the Ratio's shell out of dobby for durability, and the taffeta lining is smooth to the touch for extra comfort. The down filled face gasket at the hood and the insulated draft tube across the zipper make sure you don't feel a chilly draft throughout the night. The hood features single handed drawcords that cinch it securely around your head with a simple pull.