Are you always on the lookout for something bigger and better? Your ship has arrived with the Thermarest MondoKing 3D Mattress. Simply put, the MondoKing 3D is the biggest Thermarest mattress ever. Vertical sidewalls create 20% more usable sleep surface so you have room to sleep like starfish. Dual valves allow compressible foam core to expand and inflate quickly when unpacked. The 4 inches (10 cm) of stabilized loft provides the comfort of home anywhere. A new and improved stuff sack with easy-carry handle is also included.