Thermarest`s lightest most compact closed-cell mattress is now warmer than ever: a new aluminized surface reflects heat increasing overall warmth by nearly 20%. The proprietary foams are softer on top for extra comfort and denser on the bottom for extra durability. Wherever you’re headed the Z Lite Sol mattress is the right choice for ultralight warmth durability and comfort.
From 2020, there is a new industry standard for measuring the R-value (level of insulation) of sleeping mats – ASTM F3340-18. This new standard is the sleeping mat equivalent to the EN rating for sleeping bags.
You can now directly compare the R-value of mats rated using the ASTM F3340-18 with confidence that is a fair and accurate comparison between mats. In simple terms, the higher the R-value, the warmer the mat.
In general terms, an R-value below 2.0 is for summer use, 2.0 to 4.0 is for cooler 3 season use and 4.0+ is for winter temperatures. This will be also be dependent on your sleeping bag, how cold you sleep etc. Please contact our customer service team if you need advice on choosing the right mat for your activity.