3 Inch 5-Zone Memory Foam Mattress Topper with Plant-Based Infusion - CertiPUR-US Certified Cooling Mattress Pad for Pressure Relief - Full Size Grey Bed Topper for Back Pain & Hot Sleepers - Perfect for Guest Beds, Dorm Rooms & Home Comfort Upgrade

This was exactly as described. It expands to a full four inches. I ordered the twin size after pricing all kinds of beds for large dogs - they are expensive, especially when you are searching for orthopedic support for aging dogs. So, instead of spending $300.00 at LL Bean (yes that is the cost for a top-rated, XL, basic orthopedic bed) I bought this twin size for $75.00 and a cover for about $40.00.The topper arrived yesterday, and I was impressed that there didn't seem to be an odor. It was compressed and had to be carefully cut out of the packaging, but it was easy to stretch out on my dining room table so it could expand. After about 15 minutes it was fully expanded so I measured my pup's current bed and cut the topper for bed one. Perfect fit in his old bed cover! I was surprised that the foam was so easy to cut. It was a little challenging - it is four inches high, but overall, not that hard taking it a little at a time.Now I am waiting on the cover I ordered from Amazon to arrive so I can make the second bed. I will have some left over and I may be able to make some type of pillow with the left-over foam. Who knows????So, for a little over $100.00 I will have two dog beds made with egg crate memory foam that is firm and soft at the same time. My 90lb Chocolate Labrador Retriever loves it! He is 13 and when he tried it out yesterday - he just crashed, stretched out, and slept so well. I hope this continues to help him because he was getting more and more restless during the night on his old bed.I am truly impressed with the quality of this foam topper. I have no idea of a rating for a human bed, but it was a great buy for a homemade doggie bed.