The lightweight, self-inflating ProLite Apex compresses small and features the legendary support of Therm-a-Rest. The self-inflating foam is 5 cm thick and has a StrataCore construction that offers the best warmth-to-weight ratio of any self-inflating foam mattress. With an R-value of 3.8, adventurers can withstand the cold in three seasons with the ProLite Apex. This compact, self-inflating mattress comes with a high-quality WingLock valve, allowing it to be inflated three times faster due to the larger opening and one-way inflation. Like all Therm-a-Rest mattresses, the Trail Pro is manufactured domestically for quality and environmental reasons. A compact stuff sack is included.