Sometimes, the extra weight associated with a more comfortable nights sleep pays for itself many times over. At 8cm thick and a winter rated R-Value, our Comfort Plus S.I. Sleeping Mat is all about luxury. With a 30D stretch knit fabric applied to the upper, it feels beautifully soft to touch and being a foam mat, you don't have to worry about your sleeping being interrupted by the crinkling noise that comes with Air mats.All of our S.I. mats use the first ever, multi-function single valve designed specifically for self-inflating mats. No more fighting re-inflation as you try to roll up your mat!