Welcome! Ultralight backpacking is my passion, and keeping up on new technologies, gear, and techniques relevant to UL backpacking is what floats my boat. I'm always looking for the lightest, most functional gear to improve a lightweight or ultralight backpacking kit, and report my impressions and field testing results here. For hikers wanting to keep up on the latest and greatest ultralight backpacking gear, this is a good place to hang out. Also, there is a lot of information here (and on our informational website Southwest Ultralight Backpacking) on useful techniques and backcountry etiquette -- food for thought for hikers wanting to lighten their load and their impacts.

My goal for Ultralight Insights is to understand, test, and report on new technologies and gear of interest to lightweight and ultralight backpackers. It's a passion after all, so we just plain enjoy talking about it. I hope readers will add their own wisdom and comments, respond to my questions, ask their own questions, and correct me if I get something wrong. Happy hiking! Will

Wednesday, July 27, 2016

GEAR REVIEW: Klymit Inertia Ozone Sleeping Pad

By Will Rietveld

Klymit’s Inertia series of sleeping pads are characterized by lots of cutouts to reduce weight and act as “Loft Pockets” for your sleeping bag to expand into, increasing warmth. The pads are also thinner, and several models come with an inflation bulb and second fitting on the pad to inflate the pad firmer. This one does not have that feature; it inflates by mouth only.

The Inertia Ozone is a tapered full-length pad with an attached pillow. There are two valves, one to inflate the pad and one to inflate the pillow. Dimensions are 72 inches long x 21.5 inches wide at the head end x 19 inches wide at the foot end x 1.75 inches thick.

Closeup of the pad's cutouts (Loft Pockets) and attached pillow.

Looking at the Inertia Ozone (or any other pad in this series), one can’t help but be a bit skeptical of its comfort. There’s only one way to find out, and that is to put it to some tests.

Specifications and Features

Klymit (www.klymit.com)
Inertia Ozone
Pad, repair kit, stuff sack
30D polyester top, 75D polyester bottom
Measured weight 12.95 oz (pad only, mfr specification 12.2 oz


The comfort of a sleeping pad depends on a person’s sleeping position and the surface she is sleeping on. A belly or back sleeper can find easier comfort on a thinner sleeping pad because her weight is more distributed. However a side sleeper’s weight is concentrated at the hip and shoulder, so pad thickness and firmness matter. The hardness of the underlying surface is important too; a softer surface like vegetation or sand offers some additional cushioning, while a rock-hard surface leaves the cushioning entirely to the pad.

I tested the Inertia Ozone pad on a Colorado River rafting trip through the Grand Canyon for 16 days, and also did some testing at home to further evaluate it in relation to different sleeping positions and surfaces.

At home I slept on the pad overnight in a typical camping fashion on a hard tile floor, on a rug on top of that floor, and in a tent on the grass in my backyard (photo). The first situation is similar to a compacted campsite, the second is similar to softer ground or dry sand, and the third is similar to a vegetated campsite. I am a combination side and belly sleeper (some of both), but I can’t sleep on my back (I stop breathing, which is not good).
My first night on the pad was in the woods outside Flagstaff, AZ sleeping in a tent on hard ground. I inflated the pad as firm as I could by mouth and slept on my side. It was a very uncomfortable night.

The pad did better on my rafting trip where I slept on it several nights on dry sand. Sand is a bit softer than rock-hard ground, which helped, and I also learned that the best sleeping position on this pad is belly sleeping, and I presume back sleeping as well, although I didn’t try it. As mentioned above, belly sleeping spreads my weight out, so the pad cushions me better, and I could actually deflate it a little to make it softer.

The attached pillow works well to support my head, and I could deflate it a bit, if needed, to get it exactly the right height, or put something under the pillow to raise it.

The bottomside of the pad is slip-resistant, so I didn’t have any problems with it sliding around in a tent.

My tests at home agreed with my field testing. On the hard surface, belly sleeping is preferable and side sleeping can be uncomfortable. However, side sleeping works out better with some additional cushioning under the pad (dry sand, softer ground, vegetation); it makes a big difference in terms of overall comfort. For this pad, full inflation seems to be the best, especially for side sleeping. 

Although the pad's "Loft Pockets" may provide some benefit from allowing a sleeping bag expand into them, the feature could work in reverse for someone sleeping under a quilt, i.e. the pockets could be cold spots or  drafty. 


My opinion, after testing the Inertia Ozone with different sleeping positions and surfaces, is that its sufficiently comfortable to get a good night’s sleep while belly sleeping or perhaps back sleeping. However, if you are predominantly a side sleeper, you would probably be better off choosing a solid, thicker pad (no holes). Numerous lightweight pads are available that are 2.5 inches thick and weigh around 12 ounces, the same weight as the Inertia Ozone, sans pillow. However, the attached pillow is a nice convenience and functions well.

The Klymit Inertia Ozone can be a good choice for a belly sleeper. It's full-length, supportive, compact for packing, and the pillow is part of the pad.

Overall, if you’re a belly or back sleeper, you can get along quite well with the Inertia Ozone.


  1. This station performed superior with the rafting excursion where by When i slept on there various night time with dried crushed stone. Crushed stone is usually a little gentler in comparison with rock-hard surface, which often served, in addition to When i likewise learned that the most beneficial sleep location within this station is usually abdominal sleep, in addition to When i think returning sleep likewise, while When i didn’t try it out.

  2. Thanks for the review. I'm a back sleeper so I think this one here is not suited for me. I usually go for sleeping backs that can take a lot of abuse since we don't get a similar ground surface everytime. Price is also a consideration, although I won't sacrifice quality, durability for some substandard products - that's a given. I also camp during the winter months so the pad's R value is a consideration, too. I've recently stumbled on a site that has a list of backpacking sleeping bags that are awesome. Check it out, it might be of help http://myoutdoorslife.com/gear/camping-and-hiking/the-best-backpacking-sleeping-pad.html