Down is great, but get it a little wet and it's pretty much useless. Millet found a way to avoid this major pitfall of down by treating the down fibers with a hydrophobic coating, then blending them with a synthetic fill to resist moisture and increase the jacket's overall breathability. The Trilogy's functionality doesn't stop there, though, because with a fit that strikes a balance between comfort and mobility, the Trilogy really is an ideal insulating piece when climbing fast. The hood can be pulled over a helmet for added insulation when climbing in the high winds that accompany high elevations, while the hem and cuffs can be cinched down tight to prevent heat loss. Millet gave the Trilogy all the pockets it needs with two zippered hand pockets and a single chest pocket.