We bought a Gel Memory Foam Mattress Topper made by novaform gel by Sleep Innovations Inc. from COSTCO in April 2011. The cost for a Queen at that time was $138.99. We placed it on top of the existing mattress in the RV. We love the comfortable nights sleep it gives us. The only drawback is its heavy. The storage space under the bed is used for things we don't need access to very often. Even with the 3 inch topper on a 6 inch mattress I can use regular Queen size fitted sheets. Costco still carries this product.