Have you ever marveled at geese swimming in the one open spot of a frozen pond? They must have something special going to withstand such cold temperatures where the sun don’t shine. Essentially, they grow the world’s best insulator. Duck feathers, or down has an incredible ability to retain warm air as well as being… well, light as a feather.

Down jackets always have a number associated to them like 400, 625, 675 or 750. This is referred to as fill power—essentially a measurement of down’s loft or fluffiness. A higher number implies better quality. 750-plus is considered the highest quality down—and hard to find—but that’s often overkill and expensive because of the scarcity of premium feathers.

Down is not the only great insulator: there are great synthetic down jackets on the market too. Though down can be warmer, last longer and retain its loftiness better, synthetic down reacts better if wet, can be less expensive and more durable. Both compress reasonably well, making them excellent insulation choices when weight is an issue.

New advances in fabrics mean that both down and synthetic down now have waterproof or water-resistant exteriors. When shopping for an insulated jacket, think about your winter activity and whether you need all the technical bells and whistles, a super light layer or just a stylish and warm jacket. Here’s a look at five stellar choices to keep you warm, dry and looking good.