Nike’s out with some new technology that promises to keep runners warm this winter, but not too warm; think Goldilocks‘ third bowl of porridge. The Nike Aeroloft 800 Vest is a crazy light insulating layer that’s made from perforated down. When your body moves, the vest breathes via laser-cut holes in between the down chambers. Dri-FIT side and shoulder panels also keep the clamminess to a minimum, and the rip-stop nylon exterior is more durable than a frozen fruitcake. The vest was tested on runners in New Zealand and Japan in all sorts of conditions, and you know how those Kiwis can run.