The Sierra Designs Eleanor 20 Sleeping Bag is shaped to better fit the female form. With additional 600-fill insulation for enhanced warmth, the award-winning Sierra Designs Eleanor 20 combines all the benefits of a down sleeping bag, light weight, compressibility, warmth, with the camp-anywhere performance of DriDown. Simply put, DriDown represents the evolution of down insulation. Regular down is treated with a molecular level polymer to create a hydrophobic finish on each individual down plume. This finish allows DriDown to stay dry longer, loft better, and dry faster than regular down, keeping you warmer in any environment.