Therm-a-Rest Trail Sleeping Mat (Large) Puncture Resistance: The Toughskin's design sandwiches the mattress's Expandable Foam: Our patented expandable foam helps create a lightweight, compact core without waste. Weight: 910 grams (2lbs) Sleeping Mat Thickness: 2.5cm (1 inch) Sleeping Mat R-Value: 3.4 Sleeping Mat