Morning fitness gets frigid as the weather turns, but our Fernos Vest provides measured, breathable warmth to keep grinding out miles in frosty weather or gaining vertical. This highly aerobic, highly efficient vest warms with 40 grams of PeakFill™ Active, a synthetic circular filament fill that warms when wet and lofts back quickly when pulled from a pack. The sleek silhouette slides just as easily over a fleece or baselayer as under under an outer shell layer.