The scrupulous sleeping bag selection is something really worth your time. 

It’s valuable to do this deliberately, to not drag a useless cold  bag to throw away to the edge of the cliff at 2 am or carry a heavy one 30 km at a temperature of + 35°C outside.

Principles of choosing a sleeping bag 

  It’s especially important to know them for those who don’t have so much experience in tourism. Let’s try to figure it out with specific examples and take a few sipid models: Kelty Cosmic down 20, Marmot Trestles 30, The North Face Women’s Cat’s Meow 20 and Klymit KSB 20. These sleeping bags are roughly the same class, so the comparison will be correct. To understand the variety of models, you need to distinguish a few basic principles.

Purpose of the sleeping bag

 — Camping. You won’t carry an outfit very far, at most — from the parking lot to the shore of the lake. It should meet only one principle — comfort. Camping bags are often roomy, have a lot of nice, but not the most indispensable options, can unzip completely, turn into a blanket. They are barely applicable for other activities. 

— Hiking (trekking). These are the sleeping bags that you actually carry on yourself. Here weight and volume are already important, but subject to the requirements of temperature comfort. Here we can discuss the important dilemma — synthetic or down. The Kelty Cosmic 20 sleeping bag is filled with down and it’s ideal for low temperatures, but better in dry climates.

-Extreme. This thing for winter climbing, skiing, etc. The most important thing is the temperature of comfort. Saving money is irrelevant here. They have a heavy-duty membrane coating to protect against condensation precipitation.

-Children’s. In a sense, this is really a separate group. For instance, there are no children’s extreme bags at all. Among other things, you need to pay attention to the height of the child and how quickly he will grow out of the sleeping bag. This issue is partly solved by the presence of height adjustment.

— Female. Many manufacturers have a women’s series, and it has certain differences. By the way, the Kelty Cosmic 20 Down sleeping bag for women is shortened, insulated in the leg and thigh area and a beautiful purple color.

Basic characteristics of the sleeping bag 

  All parameters are somehow related to one another. You can simply use this scroll of parameters as a checklist.

  • Filling.
  • Comfort Temperature.
  • Weight.
  • Packing volume.
  • Origin of down.
  • Availability of hydrophobic treatment.
  • Covering material.
  • Inner material.
  • Shape.
  • Width.
  • Size.
  • Extra options.

Major selection misconceptions

These mistakes are inherent to both novices and fairly knowledgeable users.

  • Choosing by extreme temperature.
  • Choosing a heavy sleeping bag for summer hikes and paying great attention to saving weight in extreme temperatures.
  • Disregard for length figures.
  • Buying sleeping bag 1 for the whole family and for all occasions.

  We will look at all of these parameters in the Kelty Cosmic 20 review and understand the meaning of each one.

Features of Kelty Cosmic Down 20

  You don’t want to encounter surprises when you’re out in the wilderness, so it’s always best to test new gear closer to home. It seems that the Cosmic Down 20 won’t even cope with temperatures close to 0°C before its first use. However, you will stay comfortable all night long in such weather with this model. The sleeping bag also copes with its tasks in sub-zero temperatures, including the claimed -7°C, although if you get cold you should not trust it 100% in such conditions.

  Outwardly it”s not the so attractive sleeping bag, many would consider it to some it will seem crumpled. That’s quite possible, but is that the most valuable property? This model is better than many of its counterparts: 

  • the distribution of the down between the stitches is quite acceptable; 
  • the hood has optimal depth and a slightly truncated shape for a little insulation of the neck;
  • comfortable stretch closure on the hood;
  • snug footbox;. 
  • the design is equipped with a three-quarter zipper —  it is the most functional of its peers.
  • loops are provided for hanging and for attaching a hiking mat. 

   If you supplement the Kelty Cosmic 20 Down sleeping bag with thermal clothing, then a periodic decrease to -7° C won’t be scary at all. If you combine it with an inflatable mat with high thermal resistance, or sleep in a hammock, it will even be hot enough.  

   Here’s another secret that you rarely read anywhere else. If the temperature fluctuates around +5°C during the day, the Cosmic Down 20 does a great job, even at -7°C at night. But when the daytime temperature is -3°C and at night it can drop to -7°C, you will quickly feel the discomfort — it’s not only the absolute temperature at night that matters, but also the  daily average temperature. Keep this in mind!


  It’s worth getting to the real practical characteristics and comparisons after a preliminary reading. Does the sleeping bag do its job?

  The Cosmic Down 20 sleeping bag is ideally suited to the temperature of the most common conditions for most trips — 20°F ( -7°C)

   If we look at the features of the Marmot Trestles 30, that figure is 30°F (-1°C). The North Face Women’s Cat’s Meow 20 and Klymit KSB 20 have a similar reading of 20°F ( -7°C). The temperature depends primarily on the filling. The Kelty Cosmic Down 20, like the Klymit KSB 20, is filled with down — light, warm, and comfortable. The North Face Women’s Cat’s Meow 20 is filled with Heatseeker Guide faux insulation, and Marmot Trestles 30 with SpiraFil artificial insulation.

  There are three marks — comfort, limit (transit), extreme on the inside of any sleeping bag. Under no circumstances should you be guided by the temperature Extreme. In other words, you’ll be on the verge of hypothermia all the time if you choose the sleeping bag at a temperature of Extreme! If you like warmth, you should choose only the temperature of Comfort — it’s the most reliable option.


   We see in the Kelty Cosmic Down 20 review the weight is 1125 g +23 g of cover:

  • 320 g less than the Marmot Trestles 30;
  • 70 g heavier than The North Face Women’s Cat’s Meow 20; 
  • 220 g lighter than the Klymit KSB 20. 

Kelty Cosmic is a really attractive variant if you look at the weights in conjunction with the size.


   We should consider the size and packaging volume separately. The volume depends on the quality of the insulation:

  •  Packing Marmot 21.6×45.7 cm;
  •  The North Face Women’s Cat’s Meow 41×23 cm;
  •  Klymit KSB 20 40.6 x 25.4 cm. 

The Kelty Cosmic Down 20 has 2—3 times less packing volume thanks to our favorite down — it compresses perfectly.

   But if you want it to retain its properties for a long time, this sleeping bag should be stored in unfolded form.

   Growth of the sleeping bag — standard 183 cm and long. It seems better to choose a bag with a reserve of length, but that’s not quite true. Of course, it’s easier to get into the sleeping bag of a larger size than the opposite, but remember — the extra air you have to warm. However, if you want to dress harder or warm up your boot insoles then it’s the right thing to do.


   Comfort is a subjective concept, but there are still some generally accepted notions. Kelty Cosmic 20 sleeping bag is soft and lightweight. The inner material of polyester 50 absorbs and disperses moisture very well. Outer material keeps the sleeping bag dry. The North Face Women’s Cat’s Meow 20 is covered in Nylon Ripstop 20D, and Marmot Trestles 30 is covered in Polyester—it’s all good. But the Kelty Cosmic Down is covered in Nylon 20 Den with WR impregnation—water just downloads.

   Kelty Cosmic 20 is even more comfortable thanks to the pockets, the double sided very soft and slip-resistant SBS zipper with 2 runners. A little tip: use the sleeping bag liner — it’s not included, but it gives extra comfort and it’s washable, but you don’t wash the sleeping bag. The less often you wash the sleeping bag, the longer it retains its qualities.


   You’ve probably already chosen which sleeping bag is right for you. Let’s see if the price will make you happy. So of course this is not the main indicator, but let’s see:

  • Kelty Cosmic 20 $185;
  • Klymit KSB 20 $180,;
  • The North Face Women’s Cat’s Meow 20 $185;
  • Marmot Trestles 30 $ 100.

 Obviously Marmot is the cheapest option, but let’s remember that this is strictly a summer synthetic sleeping bag. The choice is yours!

Advantages and disadvantages

   Of course, there are pros and cons of Kelty Cosmic, and you probably already see them.  The minuses include the fact that the fuzz is not very fond of moisture, although it has a hydrophobic treatment. The hood area should have been made more dense or additional quilting, so that the down would not go down. In some areas there is a decrease in down density, but it does not worsen the overall picture. Rather inconvenient that all models are only with the right-side zipper — can not be connected.

   No storage sack, but you can buy a regular garment one. The size allows you to turn inside the sleeping bag, not with it — the crumpled back will get frosty if you turn around with the sleeping bag. 

   There is a carrying case, but no compression slings. But the bag will fit perfectly in your backpack between your belongings—dare to squeeze it to the minimum. Just let it fluff up for 15 minutes before bedtime.

Compare to Similar Products

   It’s hard to add anything to the Kelty Cosmic 20 sleeping bag reviews.

   As you can see, it’s optimal in all respects — light enough, minimal in packaging, environmentally friendly and comfortable. The Kelty 20 is warmer than the Marmot Trestles 30, has similar features to The North Face Women’s Cat’s Meow 20 and Klymit KSB 20, while being significantly lighter than Marmot and Klymit. The packing size is lower than all sleeping bags due to the perfect compression of the down fill.  Kelty Cosmic 20  loses only to the summer sleeping bag Marmot in terms of price, but there is a question of your choice, not the downside of the Kelty. 

 If appearance is important to you, of course you can still look for some options, but believe me, you look at the color and attractiveness only once — when you buy.  


   The Cosmic Down 20 is a versatile choice for those who need a practical sleeping bag that can be lightweight and compact at the same time, as well as providing comfort for three seasons of use. There is no doubt that this model is up to the task, especially considering that the money saved can be spent on a better backpack or tent. 

   That said, don’t consider the Cosmic Down 20 to be a cheap option, it’s more of a «bargain purchase» that pays off every penny, and in fact turns out to be much better than you expect.

   The Kelty Cosmic is the entry ticket to the world of down sleeping bag benefits.