After developing the first woman-specific bag in 1995, youd think wed have taken a break. Nope Now were combining our groundbreaking research with cutting-edge materials like Drizone waterproof-breathable membrane. Protect your lofty, warm 600-series down with award-winning Drizone and sleep better for it. All the luxurious details are still in the mix, too, including our popular tricot-lined foot box. See why Sierra Designs has become the leading provider of happy slumber for women in the backcountry.