Olee Sleep 4 Inch Tri-Folding Memory Foam Mattress Topper with Gel Infusion - CertiPUR-US Certified, Washable Cover, Twin XL Size - Perfect for Camping, Guest Beds & Temporary Sleeping Solutions (Soft, Blue)

This was not the first mattress I bought for camping in my Subaru Outback. The first one I bought was one of those blow-up air mattress types and it was horrible. Oh, it was fine at 4" thickness...until a few short hours later it was dang near flat. I returned that sucker and after researching further and reading many others comments wound up buying this dual-type foam mattress. I am literally a "Happy Camper" now!When I first opened this tri-folding mattress from the boxes and wrappers, ya, it was < 3" thick, as expected. (Pic #1). While waiting for it to expand to its full thickness I unzipped a portion of one end to inspect the construction. Just as advertised with 1" blue memory + 3" yellow foam (Pic #2). After leaving it alone for several days the mattress expanded to its advertised thickness of 4" (Pic #3). Everyone just needs to be patient at the beginning.I really like the fact that it's tri-fold because it's light and easy to maneuver. Each section is 25" X 25" and stacks neatly together when not in use and is 12" tall overall.I then took it out to my Outback to check the fit making sure I had taken my measurements correctly. I folded down both rear seats, put a fitted flannel sheet around it, then laid it on in there. Fits like a glove at 75" long X 25" wide X 4" deep (Pic #4). Then put my sleeping bag on it and crawled on in for a dry run (Pic #5).I'm 6-ft tall and must say that it does, in fact, feel comfortable enough to keep and although I have not been out camping in it until this cold winter passes, believe that I can easily spend a few nights on the road with this setup. There are several road trips I have planned coming up and will give this mattress setup a real workout. I may come back to this review and update it later with details.Seems that this is the real deal, folks. I'm hopeful that we didn't go wrong by purchasing this well made foam mattress. C'Mon Spring time! YAY!!