REASONS TO BUY
Lightweight
Compressible
Comfortable
REASONS TO AVOID
Expensive
Not particularly warm
Rab Neutrino 400 - Women's Review
This lightweight sleeping bag is a great choice for alpine climbing or fast and light adventures
The Rab Neutrino 400 is a good choice for fast and light missions with open bivys.
Credit: Ian McEleney
RELATED: Best Sleeping Bags for Women of 2024
Our Verdict
The Rab Neutrino 400 is a high-quality bag with a good warmth-to-weight ratio. It only weighs in at 28 ounces, right up there as one of the lightest bags in this review. This female-specific sleeping bag has more down per square inch than its male counterpart and is hand filled with high-quality 800 fill power Nikwax Hydrophobic Down. It is very compressible, and we love its included stuff sack. The Neutrino is not as warm as the other top contenders, having less down fill than other bags that are as light and for this, it has slowly dropped down in our rankings. We think it's a great choice for summer lightweight backpacking trips.
Compare to Similar Products
 This Product
Rab Neutrino 400 - Women's | |||||
|---|---|---|---|---|---|
| Awards |  Best Overall Women's Sleeping Bag |  Best Value for a Down Sleeping Bag | Best Value for a Synthetic Sleeping Bag | ||
| Price | $430 List Check Price at Amazon | $589 List $529.00 at Feathered Friends | $220 List $219.95 at Amazon | $169.00 at Backcountry Compare at 2 sellers | $125.93 at REI |
Overall Score  |
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| Star Rating | |||||
| Bottom Line | A great choice for fast and light adventures, the Neutrino is comfortable and compressible | The highest three-season performance of any model in our bunch | "Get Down" with this extremely well priced sleeping bag that will work for short to medium length backpacking trips in the summer | This synthetic model offers snug fitting design that is surprisingly compressible and a good choice to keep you warm in wet conditions | Too heavy and bulky for backpacking but a great choice for car camping comfort |
| Rating Categories | Rab Neutrino 400 -... | Feathered Friends E... | Sierra Designs Get... | The North Face Cat'... | Marmot Trestles Eli... |
| Warmth (25%) | |||||
| Weight (25%) | |||||
| Comfort (20%) | |||||
| Packed Size (15%) | |||||
| Features (15%) | |||||
| Specs | Rab Neutrino 400 -... | Feathered Friends E... | Sierra Designs Get... | The North Face Cat'... | Marmot Trestles Eli... |
| EN Temp Rating (Lower Limit) | 30°F | 20°F (not EN rated) | 23°F | 20°F | 20°F |
| Insulation | 800 FP European Goose Down | 950+ Goose Down | 550 FP DriDown RDS | Recycled synthetic | HL-ElixR synthetic fibers |
| Measured Weight | 1.75 lbs | 1.72 lbs | 2.36 lbs | 2.50 lbs | 2.75 lbs |
| Female-Specific Features | Women's specific fit | Extra fill in footbox and chest | Women's specific cut | Available in a "Short" length, which is a standard women's size | Women's specific fit |
| Fill Weight | 14.2 oz | 17.3 oz (medium) | 25.0 oz | 38.9 oz | Unspecified |
| Material | Pertex Quantum | Pertex Endurance UL | 20D polyester | 20D ripstop nylon, taffeta | 20-denier recycled ripstop polyester |
| Neck Baffle | Yes | Yes | No | Yes | Yes |
| Small Organization Pocket | Yes | No | No | Yes | Yes |
| Sleeping Pad Sleeve | No | No | No | No | No |
| Zipper Length | 62 in | 62 in | 39.5 in | 34.5 in | 53/15 in |
| Shoulder Girth | 60 in | 54 in | 58 in | 60 in | 58 in |
| Hip Girth | 56 in | 56 in | 56 in | 55 in | 58 in |
| Foot Girth | 38 in | 38 in | 40 in | 41 in | 45 in |
| Compression or Stuff Sack | Stuff sack and storage bag | Stuff sack and storage bag | Stuff sack and storage bag | Compression sack and storage bag | Stuff sack and storage bag |
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Our Analysis and Test Results
This lightweight, minimalist bag is packed with 800 fill power ethically harvested Nikwax Hydrophobic down. It packs down small, is lightweight, and keeps you warm in summer conditions. The Neutrino is an ideal summer bag for a frequent backpacker or alpine climber.
Performance Comparison
The Rab Neutrino will keep you cozy on all your summer backpacking adventures.
Credit: Jessica Haist
Warmth
The Neutrino is a warm sleeping bag, but not the warmest of the bunch. Rab notes that it has an EN rated at 30°F for comfort, with a limit of 27°F; we find the EN limit rating of 30°F to be right on the money. We tested this bag in Yosemite Valley on some cold shoulder-season nights, where temperatures fell below freezing some mornings, and we felt warm in this bag inside a tent, on a warm sleeping pad. Its redesigned chevron-shaped baffles are meant to keep down in place over your body and eliminate cold spots more effectively. We can't say we noticed a difference with this change.
Rab makes their women's sleeping bags 5 to 7 inches shorter in length and slightly slimmer than their men's sleeping bags, but they use the same amount of down fill for both. This means that the women's bag has more down per square inch and is warmer than the men's version. The cozy neck baffle and draft tube along the zipper kept out the cold air well. Pair it with a lightweight air mattress and you'll have a great lightweight, compact, 3-season backpacking sleeping kit. The Neutrino only has 14 ounces of 800 down fill, but it should be said that it is just as warm as the other down sleeping bags we tested with lower quality 650 fill.
Weight
Weight is the category where the Neutrino excels. Rab has made a great effort to minimize the weight of this sleeping bag by paring down its features and materials, but still retains the necessities.
Weighing only 28 ounces, or 1.75 pounds, it is a pleasure to pack this sleeping bag in your backpack. By using high-quality down, the bag can be very toasty without being bulky or heavy. We think that Rab could have used a ¾-length zipper as they have on past Neutrino models to cut down the weight of this bag even more. The shell material is very lightweight, which is great for weight savings, but is consequently quite delicate and seems more prone to molt down, which is a drawback.
The Rab Neutrino is a great choice for fast and light adventures.
Credit: Jessica Haist
Comfort
The Neutrino is very comfortable. It is on the roomy side for a mummy bag, and we never felt constricted. Its shell and liner fabrics feel light and soft against the skin as well. The bag even has an ergonomically shaped foot box so there is space for your feet as well as any wet socks or boot liners you may want to stuff in there to dry overnight.
The Rab Neutrino's draw-cord is sometimes difficult to use and we wish there were different materials for the top and bottom cords.
Credit: Jessica Haist
Packed Size
Once again, the high-quality down is to this bag's benefit, because it compresses to a small size. Rab has changed the Neutrino's stuff sack this iteration. It is a much larger roll-top design that may be water-resistant but it is less easy to compress the bag down in this large sack. This bag could potentially be compressed more with a traditional compression sack if you need to create even more space in your pack. It also comes with a cotton storage sack so you can store it away uncompressed to help keep its loft.
The Neutrino's stuff sack is larger than previous versions and we believe it can compress much smaller than this size.
Credit: Jessica Haist
Features
At first glance, this bag does not appear to have many distinct features. It is just a big blue tube. But look closer, and you will discover that many features are hidden just below the surface — literally. The main feature that Rab has introduced for its Neutrino line is Nikwax Hydrophobic down. This down treatment has been specially formulated between Rab and Nikwax in an attempt to make the down absorb less water, dry faster, and retain its loft longer. This treatment does not make the bag waterproof, nor does it take the place of synthetic insulation in wet conditions, but rather allows the bag to function at a higher level for a longer period when the weather is not ideal. Most down sleeping bags we tested now come with some hydrophobic down.
We like the Neutrino's small stash pocket, one of it's few distinct features.
Credit: Jessica Haist
The Neutrino also has more visible features like the small stow pocket for you to stash your headlamp or contact case on cold nights. We found the drawcords around the face and neck awkward to use and wish they used two separate diameter cords, they have slightly improved in the newest iteration of this product, but they're still not great.
We like the Neutrino's snag proof zipper pull.
Credit: Jessica Haist
For those of you with a vegetarian's conscience, all of Rab's down products are traceable under the European Down and Feather Association Codex, which means that the down is ethically sourced, ensuring that it is a by-product of a slaughterhouse or harvested during molting periods, not illegally live-plucked.
Value
This is one of the more expensive bags in the review, not quite as much as those right at the top of our scoring. Our testers love this bag and think it has a lot of great features to compete with some of the lighter sleeping bags on the market. However, this is no longer the only competitor in the lightweight women's category and is no longer a great value. We think there are a few bags that are less expensive, but just as great.
If you're looking for a bag that compresses down small, the Neutrino 400 is a great option.
Credit: Jessica Haist
Conclusion
This bag is constructed with high-quality materials and is warm, comfortable, and quite versatile. It is hand-stuffed with 800 fill Nikwax Hydrophobic down and is among the lightest and smallest bags in this review. It's not quite as warm or high-quality as some other bags we tested, but we still love it. Remember, ounces equal pounds, and pounds equal pain - so save yourself some pain and go with lightweight gear when you can.
—Jessica Haist
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