Moose knuckles uses a 4-tiered cold-ranking system for their outerwear: Chilly, cold, crazy cold, canada cold. The air down vest is ranket "chilly," meaning it is ultra-light and minimal. These garments should be worn to take the chill off breezy nights or as a layering option when things get colder than expected. Its shell is crafted from DWR-treated nylon and encapsulated with weightless RDS-certified 650 fill down. While an integrated hood and zip pockets provide added protection against the elements.