The Thermarest Trail Pro brings year-round warmth and legendary Therm-a-Rest support. The self-inflating foam measures 3 inches (7.6 cm) and features Thermarest's StrataCore construction, a design that provides the best warmth-to-weight ratio of any self-inflating foam construction. The Trail Pro’s 4.4 R-value allows adventurers to enjoy backpacking and camping year round. The versatile self-inflating pad features the high-performance WingLock valve, which has three-times the airflow rate of the classic valve thanks to a larger opening and one-way inflation. Trail Pro L Sleeping Mat