Marmot Hydrogen 30

The Marmot Hydrogen 30 is a lighter, warmer-weather sibling to bags like the Helium, built around the same premise of high-fill-power down in a minimal shell. At 720 g total with 312 g of 850+ fill power goose down, it targets 3-season backpacking and thru-hiking where every gram in the sleep system counts. EN testing puts comfort at 4°C and the limit at -1°C, suiting late spring through early autumn rather than winter or high-altitude use. The Pertex Microlight 20D shell is even lighter than the Quantum fabric on warmer-rated Marmot bags, and a differential cut — sizing the inner and outer shells separately — helps the down loft fully instead of compressing against the liner. Horizontal box baffles, a full-length two-way zipper, and an adjustable, contoured hood round out the feature set. Fitted for users up to 183 cm in a unisex build, it suits anyone assembling a low base weight around three-season trips rather than one do-everything bag for every condition.