A couple of years ago my very VERY old mattress was overdue fir replacement. Sagged and was not supportive. I was unable to buy a new mattress & box spring so I bought the Dormeo Topper to hold off discomfort for a while.
Fantastic purchase! The queen size cost me about $300. It arrived in a matter of a few days. Delivered in a box, rolled up tight and wrapped in plastic and protected by its own duffle bag. It was easy to manage to get it on the bed and "released" on top of the mattress. It expands gently and the support quality is very soon evident.
I slept on it for two more years and it made my sleep very comfortable. It has wide, adjustable bands in each corner that stretch under the corners of the existing mattress so it stays put on the mattress and does not shift or bunch. It's all individual coils of firm foam, firmer under the hip and shoulder area. It's not a flat slab of memory foam. Relieves pressure points and gives a firm but comfy surface. Fits under any mattress cover. My fitted sheets were a little snug because I added the 3" topper, but they definitely still fit. I did mot have to buy new sheets with deep pockets. Yes, it made the top of the bed higher off the floor!
The Dormeo Topper is very cool to sleep on. Not sweaty and it is perfectly quiet and gives off no smell. They suggest letting it expand for a few hours and to walk on top of it, all over, to make sure it revived from the compression more evenly. I gave it brief treatment in my stocking feet. Don't think it was necessary. But I did let it breathe for a couple of hours before putting linen on the bed.
Highly recommend it. Does everything the video and ads say it does and worth all the money. Very sturdy and holds up over time. I was able to wait to replace my crummy mattress by having the topper.
I did buy a new mattress and foundation just this January, so my dear Dormeo topper is rolled as best I could do with a friend to help, and tied carefully, now stored in the house. I'm so wanting to give my Dormeo topper a new home. It was just as good as new after 2 years. So I know it's a great solution to a mattress that is deficient or if you need relief at pressure points. It makes a big difference, almost like buying a new bed.
Hope I've helped, If you have specific questions, post them and I'll answer. (If you're anywhere near Brooklyn I'll give mine to you to enjoy!)