Therm-a-Rest Z Lite SOL: The Foam Sleeping Pad That Never Goes Flat

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Some gear gets better every year. Some gear was right the first time. The Therm-a-Rest Z Lite SOL belongs in the second group: a folding foam pad that has no valve to fail, no air chamber to puncture and nothing to inflate at the end of a long day. Fold it out, lie down, sleep. Here is what it is, why so many hikers still strap one to the outside of their pack and where to buy one.

What it is

The Z Lite SOL is a closed cell foam sleeping pad from Therm-a-Rest, made in the USA. Instead of rolling up, it folds like an accordion into a compact rectangle, which makes it fast to deploy and easy to stash. The surface is molded into a pattern of raised peaks and hollows, and one side has a reflective metallic finish.

That shiny side is the SOL part of the name. Therm-a-Rest calls the coating ThermaCapture and says it boosts warmth by 15 percent by reflecting radiant heat back toward you. The pad carries an R-value of 2.0, measured to the ASTM F3340-18 industry standard, so you can compare it fairly with other pads. If R-value is new to you, our guide to sleeping pad R-value explains what the number means and how to use it.

Sizes and specs

• Small: 51 inches long and about 10 ounces.
• Regular: 72 inches long and about 14 ounces.
• Width: 20 inches.
• Thickness: 0.75 inches.
• R-value: 2.0 (ASTM F3340-18).

The Small is the one many ultralight hikers choose, since it covers shoulders to hips and lets a pack or spare clothes take care of the legs. The Regular gives full length coverage for anyone who prefers it.

Why it is cool

The appeal is reliability. An air pad is more comfortable, but a foam pad cannot leak. You can throw it down on rock, gravel or a hut floor without thinking twice. That makes the Z Lite SOL a favorite as a backup layer, a sit pad at lunch breaks and a base for kids who are hard on their gear.

It also plays well with other pads. R-values are additive, so a foam pad under an inflatable one adds its insulation to the system. Therm-a-Rest uses the example of a NeoAir XLite NXT at R 4.5 stacked on a Z Lite SOL at R 2.0 for a combined 6.5, which is a setup many people use for cold weather and winter camping. We cover the inflatable half of that pairing in our NeoAir XLite NXT review.

Then there is speed. There is nothing to blow up and nothing to deflate. In the morning it folds flat in seconds and straps to the outside of a pack, which frees up space inside for food and layers.

Who should buy it

The Z Lite SOL suits thru hikers and weekend backpackers who value simplicity, campers who want a second pad for cold nights, and families who need durable pads for kids. It is also a smart pick for anyone new to backpacking who wants a pad that will last a long time and never needs a repair kit.

If comfort is your top priority or you sleep on your side, a thicker inflatable pad will feel softer. Many people end up owning both, using foam alone in summer and pairing the two when temperatures drop.

Build the rest of the kit

A pad is only one piece of a good night outside. A compact stove like the MSR PocketRocket 2 takes care of hot food and coffee, and the Helinox Chair One is the luxury item people stop teasing you about once they sit in it. If you want a sleeping bag you can wear around camp, take a look at the Poler Napsack.

Care tips

Foam needs very little care. Keep it clean, let it dry if it gets wet, and store it flat or loosely folded at home. Because the pad sits on the outside of many packs, it can pick up scuffs, but that does not affect how it insulates. Face the reflective side up toward your body when you want the extra warmth from ThermaCapture.

Where to buy

The Z Lite SOL is sold directly by Therm-a-Rest and by outdoor retailers in Small and Regular lengths. Check which length suits your height and the way you sleep before you order.

For more gear picks, browse our buying guides.