WARMTH WITHOUT THE BULK – The Whitney women''s lightweight down jacket with hood features a 90/10 white duck down insulation with a lofty 750 fill power rating. The down is compressible, allowing for a jacket that is not only warm and lightweight, but packable as well.r HYDROPHOBIC NANOTECH - A patented hydrophobic nanotech coating is applied to the durable two tone outer layer fabrication. The hydrophobic nanotech DWR coating provides resistance to moisture, while the outer layer fabrication provides a durable first layer of protection.r TRUE TO SIZE: Designed for a true to size fit, our lightweight winter jackets provide an optimal fit that is neither too tight nor too loose. Please feel free to contact us for questions regarding sizing.