Are you always on the lookout for something bigger and better? Your ship has arrived with the MondoKing 3D. Simply put, the MondoKing™ 3D is the biggest Therm-a-Rest® 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. A new and improved stuff sack with easy-carry handle is also included.