Used only once for camping since purchase. I believe that blocking the cold from the ground is the key to comfortable sleep when winter camping. If you layer a mat with an R-value of around 4 on top of this, the total R-value will be around 6, so you won't feel the cold from the ground. I will also include bands purchased from a 100-yen shop so you can bundle it up. Purchase price: 9790 yen ● Manufacturer color notation: Silver/Lemon ● Size when in use (cm): W51 x H183 ● Size when stored (cm): W51 x H13 x D14cm ● Weight (g): 410 ● Thickness (cm): 2 ● R-value: 2 ● This is a 3-season closed-cell mattress that can be folded like an accordion for storage. Aluminum is vapor-deposited on the surface of the Z Lite Sol. Compared to models without aluminum vapor deposition, the insulation performance is improved by 20%. (Z Lite does not have aluminum vapor deposition) The folding type can be quickly unfolded and stored, so you can easily take it out and use it without stress, even for short breaks.