A down jacket is a jacket lined with down, often from goose or duck. The outer fabric is often treated with waterproofing to better resist moisture. The down's good thermal insulation makes down jackets popular in cold climates. There is everything from thick down jackets to thinner, more lightweight models. The lightweight down jackets are perfect during autumn and mild winter, but also as a mid layer under a shell jacket when the temperature drops. For really cold days during the winter or for low-intensity activities, we recommend thicker winter jackets with a higher fill power. If you want to know more about down insulation and fill power, look at our guide on insulating clothing. Match our down jackets with a warm and comfortable beanie for men to stay warm and cozy.