One of the most amazing things about the super light Phantom Jacket is that size for size it weighs less than the Mountain Hard Wear Sub Zero Vest. That's sort of like wearing insulated sleeves for free. High quality 800-fill European goose down insulation is the key component in this scale-tipping phenomenon resulting in one of the best warmth-to-weight ratios you'll find in the industry. Unlike other lightweight or minimalist designs that cut features to shave ounces the Phantom has all the pockets (four) and coverage (dual hem drawcords and a lower back waist pull adjustment) that you count on when you're days from the trailhead. Now you can lighten up without compromising your standards.