The Men's Mythic G Down Jacket is Rab's lightest, most packable insulator for any cold-weather endeavor. Summer alpine treks and winter backcountry tours are all the lighter thanks to this jacket's phenomenal 1000-fill down insulation, which holds the highest fill power out of any Rab down jacket. It has the highest warmth-to-weight ratio, which means it's remarkably light compared to other jackets that are just as warm. A thermal-reflective lining enhances warmth even better, and a Pertex Quantum shell adds windproof, water-resistant protection from the elements.