Incredibly light, the Arc'teryx Men's Cerium LT Down Jacket weighs in at just under a half pound, but still packs a wallop of warmth. Warmth that comes to you in hybrid form, thanks to Arc'teryx placing 850-fill goose down where it matters most (your torso and arms), and then synthetic Coreloft insulation in locations that are likely to suffer exposure to moisture, like the shoulders, collar, and along the hem. The dynamic duo of high-tenacity Arato 10 face fabric and high warmth-to-weight down insulation fights cold on cloudless, bitter days. Wear this hybrid jacket over a thermal-weight baselayer when you're hiking in a cold snap, and wear it under a waterproof hardshell if you're skiing through a snowstorm. Whatever your pleasure, the Cerium jacket keeps you warm without being a burden, either on your back or in your pack. Its trim silhouette means you can layer over the Cerium and still put your arms down comfortably by your sides. Underarm articulation gives you upper-body mobility so you can plant a pole or chuck a snowball without tearing seams or exposing flank flesh. Light elastic cuffs won't pinch your wrists but will rebuke cold air attempting to slither up your arm. A chin guard on the collar prevents unattractive zipper rash caused when cold metal chafes against your chin. The included stuff sack makes it easy to pack this jacket when you're taking off for a week in the Winds and you need something warm for nighttime when the sun sets and crumbs from dinner have disappeared into the dying fire.