Womens Juel Vest S - Rabbit/Rabbit. The Juel is an ultralight vest designed for high performance with minimal weight and bulk restrictions. The Juel vest is insulated with 850 fill power DownTekâ¢, an insulation that absorbs less water and dries faster than untreated downs. The exterior is comprised of an ultralight nylon rip-stop shell that is both water and wind resistant. This is the go-to high performance layer.