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, the Comfort Plus S.I. Rectangular Mats provide luxury in a packable size. A 30D stretch knit fabric is used on the top layer for a great next to skin feel, and a lightweight 30D polyester with extrusion laminated TPU is used on the base for increased durability.