Don't let the light weight fool you - the MST Synthetic Down Pac Jacket is incredibly warm and versatile. The jacket is packable and zips into its own vertical chest pocket, making it the perfect size for stowing in a blind bag, ATV, or boat. The jacket is water-repellant so you can wear it alone as an outer layer, or under waterproof outerwear when you need an extra layer of insulation. Synthetic down is ultralight, has uniform loft throughout the garment, and won't mat down like natural goose down.