SPECS: 6.5 R-value DESIGN & DETAILS: Self-inflating sleeping bag that features four inches of comfortable plush foam Upper surface is designed with 30D stretch knit fabric that feels luxurious and warm in cold temperatures and cool when your body runs warm The flip-over multi-function valve prevents air from being drawn in which makes it easy to pack up your pad PillowLock system prevents your pillow from slipping Delta Coring removes 40% of the foam without removing the comfort, so you're let with a lightweight, comfort-forward mat that won't weigh you down