The tapered design of the Rab Neutrino 600 down sleeping bag means it cuts excess bulk, a very good thing if you’re having to hike through alpine environments - the kind of setting this sleeping bag was designed for. There are draw cords on both the hood and the shoulder baffle, so things can be tightened up if things get truly Baltic.

OEX Leviathan EV 900 Down Sleeping Bag | Millets

In general, then, fill power is a useful marker for understanding how much down you might need to achieve the same insulatory effect. Zippered gills on the front of the bag let you fine-tune the bag’s warmth without fully unzipping and exposing your body parts to the cold. They’re often also coated with a hydrophobic damp proof system, designed to allow the bag to retain its warm, loft and fill even when in clammy or wet conditions. On the other hand, down-filled higher-end models with an equivalent temperature rating may get as light as 850g and pack down to the size of a soccer ball.The outer shell of the bag is coated with a PFC-free water-repellent that beads water and repels moisture.

OEX Leviathan EV 900 Sleeping Bag | Millets

The fill is treated with a hydrophobic finish, while the shell fabric is made from Gore-Tex Infinium. I’ve always been impressed by its performance, be that on a rainy thru-hike of Germany’s Black Forest National Park, dozens of winter nights in and around Snowdonia’s Glyderau, or 10 chilly October nights in Wyoming’s Grand Teton National Park. It utilizes superfine yarns bound together with special resins to mimic the properties of natural insulation such as down. You can trust Advnture Our expert reviewers spend days testing and comparing gear so you know how it will perform out in the real world. The OEX Leviathan EV 900 is a lightweight and compact 4 season sleeping bagthat willkeep you warm intemperatures down toaround -16°C, and still safe as low as -38°C.It relates to the loftiness of the down itself, and generally speaking, the higher the number, the better the quality (with 900 fill power being the best you can get). When it’s warm, the dual zippers let you fold back the top of the sleeping bag like a quilt, providing a lot of venting.

OEX Leviathan EV 900 Sleeping Bag | Blacks

Despite the best efforts of the outdoor industry, be it in the form of hydrophobic or Teflon coatings, the feathers will still lose their loft when they get damp and thereby lose much of their ability to keep you warm. Hell, just head into the Lake District in mid-January and take a peek into the various tents you spot. Where other bags use horizontal or vertical baffles to hold insulation, this one uses trapezoids for thermal efficiency and to keep the bag from having cold spots. It comes with a compression stuff sack to help you optimise packing space - using the compression stuff bag, it will pack down to approximately 33cm x 27cm. Not that you want a completely waterproof sleeping bag anyway – that’s what bivy bags are for and a zero breathability sleeping bag sounds like a sticky night’s sleep.

Will keep you comfortable in hostile wintry weather, filled with Hydrophobic fill keeps you warm even if damp. Be honest with yourself about how you’ll use it, and let this inform the type of bag you really need.

OEX | OEX Sleeping Bags For Sale | GO - GO Outdoors OEX | OEX Sleeping Bags For Sale | GO - GO Outdoors

One option I was considering was getting an Alpkit Skyehigh 900 + Hunka XL + Thermarest NeoAir Xtreme + Alpkit Masson sleeping bag liner, would this work? The OEX Leviathan EV 900 is a 4-season down-filled mummy sleeping bag sold by UK outdoor retailers GO Outdoors, Blacks, Millets and Ultimate Outdoors.

We’ve slept in it in all weather on Dartmoor National Park (including a super chilly deep winter camp where the mercury without wind chill hit -13 degrees Celsius), and we even used it at the height of the summer on a large meet up when all other bags were taken. We’d bet that you’d see the Leviathan’s unmistakable off-yellow hue emanating from at least a quarter of them. The microlight 1400 might not be as featherlight, packable or quite as sumptuous feeling as down-filled sleeping bag, but it is certainly light enough to be taken on backpacking adventures, and is more that capable of keeping you warm in most conditions likely to be encountered during the vast majority of the year in non-alpine terrain. While it is more expensive than some other sleeping bags on the market, its advanced materials and features make it a worthwhile investment to ensure you’ll be camping comfortably.