The Klymit KSB 20 Sleeping Bag: Comfort for Sleepers of All Shapes and Sizes

Sleeping in the great outdoors can be a beautiful, yet uncomfortable experience, if you choose the wrong sleeping bag.

A night under the stars is always a treat, unless, that is, you’re huddled up freezing in a sleeping bag with insufficient insulation for the climate, or which gets soggy from the rain, or which feels so restrictive that you can barely move inside it.

A bad night’s sleep is the fastest way to bring down your morale on a camping trip, so avoid these issues by choosing the right sleeping bag to meet your needs. The Klymit KSB 20 Sleeping Bag is a three-season sleeping bag made to keep you comfortable, warm and even dry all through the night.

Note: We get commissions for purchases made through links in this article

Product Specifications

  • High-end lightweight synthetic sleeping bag
  • Compact, comfortable, and designed with detail
  • Flexible stretch baffles that HUG your body and eliminate air movement
  • Neck collar to minimize heat loss
  • Adjustable bag length
  • Measurements: 84.5″ x 31.5″ x 21.7″.
  • Weighs only 2.75 lb
  • Temperature Rating: 20 degrees Fahrenheit, -7 degrees Celsius

Check the price on Amazon

Innovative design and technology is leading to new levels of comfort in outdoor gear these days, and the KSB 20 is a perfect example. It combines traditional white-duck down filling, with a hydrophobic nylon shell to keep you dry and overcome the usual downfall of down sleeping bags, which is their poor performance in wet conditions.

Elastic thread has been used to sew the baffle seams, turning the classic mummy shaped sleeping bag into a unique cocoon which can both shrink down to fit your body and also stretch with you as you move. This makes for both a warmer and more comfortable sleeping bag, no matter what your body size or sleeping style.


Klymit have created a versatile and user-friendly sleeping bag, so let’s dive in and take a closer look at the specific features of the KSB 20.


The KSB 20 has been designed for great packability and storage during both the on and off seasons. The bag itself is highly compactable, a real bonus of going for a down bag in general. It stuffs down into an included stuff sack which users report comes down to about half the size of most mummy sleeping bags.

Klymit have given quite a bit of thought into how you can best store this bag during the off season. Keeping your sleeping bag, especially a down bag, squished up in a stuff sack all year round can have dire results for your insulation material and the constant compression reduces loft.

The KSB 20 comes with an additional mesh storage bag, which won’t squash your sleeping bag. Alternatively, there are hanging hooks sewn onto the footbox, so you can hang your bag up when not in use.

How you store your sleeping bag when you’re not on a trip will depend on the amount of room you have, and Klymit really has your back here no matter what you’re living space.

The hanging hooks are also really handy for hanging your sleeping bag out in the sun for drying after washing, or even if you bag accidentally gets wet during your trip.

Design and Durability

This sleeping bag performs reasonably well when it comes to durability. As a rule, down insulation lasts longer than synthetic insulation.

Synthetic materials tend to compress and lose their loft after a few years of use, whereas a down sleeping bag like this one should last far longer without losing loft or warmth over time. Proper storage, using the provided storage sack or hanging loops will also help to keep the KSB 20 in top condition.

The lightweight nature of the bag gives rise to questions about the durability of the materials used, since ultralight equipment often sacrifices durability for reduced size or weight. The 20 denier rip-stop nylon fabric is designed to avoid nasty tears from sticks, rocks and other debris.

Rip-stop materials have been reinforced with heavier threads, making them more durable. Nylon has a high strength-to-weight ratio, resisting damage without needing to be extremely heavy. It’s commonly used in outdoor products, especially high quality items, so it does have relatively high durability.

The KSB 20 comes in black and red options. If you’re going to be sleeping in an enclosed area like a tent where your tent in unlikely to come into direct contact with the ground, feel free to choose the red.

Black always hides dirt easily, so if you plan to sleep directly under the starts, setting up your sleeping bag on potentially bare ground, it’s probably the best colour choice to keep your bag looking clean and fresh over the years. This bag is also durable to put through the washing machine after muddy trips.

Klymit have added a few thoughtful design elements which add to the performance of this sleeping bag. A three quarter length side zip is long enough to get in and out of the bag easily, but also avoids cold spots around your feet, where people lose much of their body heat.

Some users have complained that the zipper tends to get caught, which can be a tearing hazard for the surrounding fabric, but users report that rips are uncommon. It also has a full length zipper guard to prevent drafts from getting inside.

A small stash pocket on the inside of the bag gives a handy place to store small items that you don’t want to lose, like your wallet, or you could use it to listen to music at night with an mp3 player or phone.

Weight & Size

One of the main things which draws backpackers to this tent in the minimal weight. At 2.75 lb, it is a good lightweight option. True, it’s not the absolute lightest sleeping bag on the market, but it provides a good balance of weight and functionality.

The nylon fabric and down insulation both provide exceptional benefits considering their low weight and compressibility for easy packing that doesn’t get in the way when you’re on the trail.

Initially this sleeping bag seems small, but look again! Klymit have used stretch baffles, meaning they have sewn the seams with elastic. This choice has made for an incredibly stretchy bag which can accommodate more than you would think just looking at it.

Perfect for people who tend to stretch or move around a lot in their sleep, as well as larger people who may find sleeping bags a bit restrictive for them. Klymit actually offer an oversized version of this sleeping bag, for even more space.

Technically, this is a mummy-shaped bag. Mummy bags have a slim, body-hugging fit for maximizing warmth while cutting down on weight and bulk.

The downside to mummy bags is that they feel just like that – as if you’re a mummy in a sarcophagus! They can feel very constrictive and even claustrophobic, offering little space for movement.

Klymit have come up with a fantastic solution in the KSB 20, capitalizing on the benefits of a mummy cut, without any of the typical drawbacks! The length of this bag is adjustable. The loops which can be used to hang the bag if needed are actually length locks, which can be used to reduce the length of the bag up to 15 inches.

It may not seem to be a big deal if a sleeping bag is long on you, but extra interior space always means more air which needs to be heated, so shorter people might want to make use of the length locks to keep the insulation as efficient as possible.

The length can go down to fit a person of 5’3’’ height. The standard size measurements are 84.5″ x 31.5″ x 21.7″.

Warmth & Temperature Rating

With a temperature rating of 20° F (-7°C), the KSB 20 can handle some pretty chilly nights. While still classed as a three-season sleeping bag, it’s on the border of being suitable for winter too, depending on your expected climates.

This bag may not be able to withstand alpine temperatures, but it should keep you warm in most locations all year round.

It’s definitely worth researching the temperatures your destination experiences before deciding to buy an additional winter sleeping bag, at least.

The faux-mummy shape of this bag designed precisely to keep you warm. Mummy sleeping bags are meant to keep the interior bag space to a minimum so that pockets of cool air can’t exist between your body and the insulation.

If your sleeping bag needs to work to keep the interior air at a higher temperature, that means less warmth for you!

The KSB 20 does this, but even more than standard mummy bags. The elastic seams snuggle right up to you, creating a cocoon around your body with no dead air space. This means that the full power of the down insulation is being used to keep your body warm, with no need to heat the air around you.

Klymit have incorporated some extra features to maximize the thermal performance of this sleeping bag. There is a neck collar to keep out drafts, as well as a mummy drawstring hood to keep your head warm. 650-fill duck down provides plenty of loft and warmth, while remaining breathable.

Water Resistance

Water resistance is always a big factor with sleeping bags, since nobody wants to wake up during the night only to find that they have been sleeping on a soaking wet sack!

Lack of sleep due to a wet sleeping bag can really put a ‘damper’ on a camping or backpacking trip, especially if you have to get and go the next morning without the time to dry your bag out properly before packing up.

While down bags are superior to synthetic ones in most respects, they do tend to perform worse when it comes to getting wet. Down loses its shape and warmth when wet, far more so than synthetic insulators.

Down also dries slower, meaning that you might be stuck with a wet sleeping bag for days unless you can afford to stop and hang it out in the sun (if the weather permits).

If you know you’ll be setting up camp in a rainy or humid climate, consider going for a synthetic bag or make sure that your tent is really waterproof.

The nylon shell of the KSB 20 has been coated with a durable water repellant (DWR) treatment. In moderately wet climates this should be enough to protect the insulation from moisture, but do be aware that “water repellant” is not “waterproof” and you should try to keep your bag as dry as you can.


The KSB 20 is a very comfortable bag for even the most restless of sleepers. The flex baffles can really stretch due to the elastic stitching, so the bag can easily adjust around your body’s movements. In a sense, this bag is almost tailored to each individual user as it reshapes itself according to your body size and shape.

People who stay still during sleep will feel cozy as the elastic shrinks to form a cocoon around them, while people who toss and turn during the night will be unimpeded by the flexible materials. Extra room has been given in the half-moon footbox, retaining warmth as well as giving more space for your feet.

The chest area has also been expanded to add girth for added freedom of movement and space to avoid a restricted feeling. This has been done is such as way as to retain the expected level of warmth.

The nylon fabric, according to Klymit, feels like a ‘silk sheet!’ Whether that’s really accurate or not, it’s definitely a soft and relatively comfortable fabric. The hood has also been fully insulated to provide a soft place for your head to rest.

Some sleeping bag hoods are just there to protect your head from drafts, but Klymit have added a nice touch with this cushy hood, which could even be used as a pillow.

If you get too hot at night, or want to use this sleeping bag for summer nights, the zipper is two-way, so that you can open it from either the top or bottom for ventilation where you need it.

Value for Money

This sleeping bag has a middle range price. Down bags are generally more expensive than synthetic ones and the KSB 20 provides a good compromise between quality materials and a reasonable price.

Compared to many down bags, this is a very affordable option, giving you the extra loft and warmth that you would expect in a down bag, but without the hefty price tag that many high end bags demand.

The mid range price has kept this a three-season bag, since there isn’t enough insulation for really extreme temperatures, but most campers who only venture into the backcountry during the on-season would find this bag more than meets their temperature requirements.

The thoughtful extras that Klymit have included, such as the elasticized baffles, padded hood and oversized footbox, make this bag a bit of an upgrade over the basic mummy sleeping bag. Overall, Klymit have presented a versatile and comfortable product at a competitive price.

Competing Products

Sleeping bags these days come in all sorts of shapes and materials, so be sure to look at a few options before coming to your decision. Take a look at these competing products to see where the KSB 20 stacks in the marketplace:

Hyke & Byke Quandary 15 Degree Sleeping Bag

The Hyke & Byke Quandary 15 Degree Sleeping Bag offers a slightly lower temperature rating of 15° F, making it a good option if you need just a slight increase in warmth. Like the KSB 20, this is a down bag, with a hydrophobic treatment to prevent moisture getting in.

It doesn’t have the elasticized stretchy baffles, so this may be a better option of you prefer a more structured bag and don’t tend to move around a lot in your sleep.

Hyke & Byke are a relatively new company that make a big deal about having lower prices due to keeping their overhead costs low because they claim to run their business completely on the “cloud.”

Kelty Cosmic 20 Degree Sleeping Bag

The Kelty Cosmic 20 Degree Sleeping Bag is another 20° F bag, this is a simple, conventional mummy bag. Perfect for minimalists who want a compact, light and hassle-free option, without worrying about all the bells and whistles. This bag is polyester fabric with DriDown insulation.

DriDown is a water-resistant down technology, meaning that the down, which is notorious for handling water badly, should keep its loft and insulating properties even in rain and moist weather.

It has a draft collar and hood to keep you warm as well as a zipper draft tube for extra protection against cold breezes. This is a great option if you plan to camp somewhere you’re likely to get rain and chilly winds!

Outdoor Vitals Summit Down Sleeping Bag

The Outdoor Vitals Summit Down Sleeping Bag is a bag that’s been designed for lightweight backpackers. With a weight coming in at 2lb 6oz, it’s easy to carry and it comes with a compression sack so it will take up minimal room in your pack.

A mummy bag with a temperature rating of 20° F, this down bag has 800 fill power, making for plenty of loft. Grid baffles work to keep the insulation in place to prevent cold spots.

A lot of sleeping bags can quickly wear out around the zipper, especially since low quality construction can cause zippers to get caught and risk tearing the surrounding material. This bag has been made with heavy duty YKK zippers to keep your bag usable for years.


Klymit’s KSB 20 is especially suitable for people who don’t like to sleep in a constricted space. It can really start to feel cramped sleeping in a narrow bag, inside a small tent. Especially when outside of your shelter is the wide open space of the outdoors.

This sleeping bag is perfect for people who crave the extra room to move that few sleeping bags offer.

Aside from the comfort offered by the stretch baffles, you also get a warm and cozy bag which will conform to your body shape to keep you well insulated in most climates. The hood and neck baffle keep out drafts and down fill is always the warmest option for insulation.

Overall, this bag is well designed to keep you both warm and comfortable whatever your sleeping habits. Still, it’s not perfect:


  • Down insulation provides good level of warmth and long-term durability
  • Hydrophobic material
  • Stretch baffles for extra warmth and comfort
  • Can move around a lot, unlike most mummy sleeping bags
  • Rip-stop material for extra durability
  • Hood is cushioned for pillow-like feel
  • Comes with additional storage sack as well as stuff sack. Can also be hung using attached loops.
  • Contains an interior pocket for keeping personal items
  • Double-side zipper opening for better insulation
  • Soft material feels nice on skin
  • Length can be adjusted


  • Down insulation is susceptible to water and moisture
  • Zipper can get caught
The Klymit KSB 20 Sleeping Bag
  • Packaging
  • Design and Durability
  • Weight & Size
  • Warmth & Temperature Rating
  • Water Resistance
  • Comfort
  • Value for Money and Guarantee


The Klymit is a warm, comfortable mummy style sleeping bag designed for three season use, with a twist. It is light and flexible for comfortable movement and a range of extra features that to improve usability whilst camping. It is water resistant, made from high-quality materials and is specially designed to keep in good condition even when not in use.

User Review
0 (0 votes)

What’s your favorite sleeping bag shape? Mummy bags are good for keeping your body warm and your pack size small, but are they really comfortable enough? Leave a comment to share your opinion about whether the mummy shape still has a place in modern camping, or if it’s time to move on from these restrictive sleeping bags.

3 thoughts on “The Klymit KSB 20 Sleeping Bag: Comfort for Sleepers of All Shapes and Sizes”

  1. Out of all the brands you mentioned, Kelty Cosmic 20 Degree Sleeping Bag is the top 1 for me. It is super comfortable and makes camping trips a lot more enjoyable and fun. It will really keep a person warm and cozy. I will gladly recommend it to everyone. Great review by the way.

  2. Klymit KSB is a high-end synthetic sleeping bag that comes highly recommended by most users. This is by far one of the most comfortable bag for the money.


Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.