The Marmot Hydrogen has had a lot of work put into its design, and it shows in the detail. Hidden inside the high-lofting (fluffable) body, the baffles have stretch, allowing the inner and outer to move independently. This maximises down loft and minimises strain and therefore wear and tear on the shell fabric and stitching. The double-ended zip is full-length with an internal baffle and anti-snag strip. The zip ends in a curved section at the hood to stop accidental opening, and with a down flap protecting your face there’s no need for a Velcro tab or zip ‘garage’. The hood itself is protective and warm, and it cinches in well with an external drawcord, which is useful for keeping out the cold as there is no shoulder baffle. It has a down-filled baffle around its edge for user comfort. The Marmot Hydrogen is a comfortable bag as the fit is quite roomy with enough space to move your arm and knees freely. The foot box is shaped to allow a natural foot position. The bag has hanging loops and comes with a stuffsack and a storage sack.
Weight (bag only) 720g
Size (length x shoulder width x foot width) 220x45x76cm
Packed size 26x17cm
Outer fabric 20D nylon mini ripstop
Inner fabric 20D nylon mini ripstop
Insulation 850 goose down
Construction stretch tricot baffle
Comfort temperature rating +4 deg C
Lower comfort limit -1.2 deg C
Extreme temperature rating -17.2 deg C
The Marmot Hydrogen is a very well-thought-out product that is very comfortable to use but the added roominess does push the weight up to 720g for a -1.2 deg C bag.
Review by Peter Macfarlane
First published in Trail magazine June 2012