Firm as expected. It expanded within 24 hours of taking it out of the packet. Woke up with much less back pain. It works for me and I love it!

It is a good product.

My husband loved this. He put it in his rv and said it helped so much.

My product arrived just as stated . 4 inch in depth and perfect twin size i love it is med firm. My experience with delivery to product was good, and no chemical smell at all! Functionality is good.

I got this mattress topper on sale for about half its normal price. It fluffed up to full thickness after about four hours and is supportive and comfortable if you prefer a firmer mattress. We placed a pillowtop cover over it, and it's made our bed comfortable enough that we're both sleeping marginally better. The corner straps are nice to keep the topper in place, and the included cover is nice and soft.The worst part of this is that it's square, so whichever way you place this on a king size bed, it hangs over each side about two inches. With the sheets on, you can't really see it, but we both have a tendency to sleep on the very edge of the bed, and it's a little precarious. I've woken up more than once thinking I was going to fall out of bed.It's also been five days, and the topper still stinks strongly of chemicals.If not for the smell and the poor fit, this would have been a favorite purchase. But I feel like for a $200+ mattress topper, we could have done way better.

Rating: ★☆☆☆☆Title: Extremely Disappointed – Too Big, Not 4 Inches, and Overwhelmingly Extreme Strong Odor!!!Review:Buyer Beware!!! This topper is a huge letdown. Doesn’t meet the advertised description at all or my expectations. It’s significantly larger than my Twin-size mattress, which causes it to hang off the sides and shift around. It’s also not 4 inches thick as advertised—more like 3 to 3.5 inches at most. Worst of all, the chemical smell is overwhelming, made me sick to my stomach, even after airing it out for days and spraying It with an odor eliminating spray. I wouldn’t recommend this, especially for anyone with or without allergy sensitivities, and/or limited small living space.

So far so great! Our mattress, even though it was expensive when we bought it, started to become very unsupportive with dips. I was getting bad back pain in the mornings. We decided to try this topper rather than drop $$$$ on a new mattress. This topper is great! I love it. Yes, it is firm but it is exactly what I wanted. I no longer feel the dips of the mattress underneath. Now that I'm almost 50, I need the firm support, yet there is a give to the topper, allowing for comfort on the shoulder when sleeping on the side. You do need to get sheets with deeper pockets. I'm very happy we went with this topper rather than buying a new mattress. It fits great on my queen mattress, no smell after 24 hours of airing it out and letting it fill out per the directions.

A few thoughts on this.1- This is N O T 4" thick.Maybe 3".Deeply annoyed by this, as I spent hours & hours researching various pieces to replace the 4" mattress topper I had, and loved, for years.Yes, it had the appropriate amount of time to expand; truthfully, it expanded to its full not-4"-thickness in about half an hour and did not expand further.As my previous mattress topper had been removed already, & was pretty crumbly, I thought, alright, well, let's give it a go.2- This may be a matter of time, but it SO does NOT give you that "being held", squashy, lush feeling. I Perhaps after a few uses, it will cease to feel like a spongy plank. Granted, I was looking for support to relieve serious & severe pain- I've got OA & awful bone structure - some scoliosis, moderate / severe OA everywhere (back / discs / facet joints, hips, legs, feet), a history of dislocations (hip, knee), and chronic pain.So I acknowledge there is an adjustment period.3- Despite my profound irritation over this item not expanding to anything like 4", I figured I'd give it a try.4- It is extremely nice to sit on. Supportive, firm, and one feels supported, & less inclined to slouch.5- Grudgingly, I can say that it does help with pain. It's not quite as described, but I was surprised to get up upon waking to find I wasn't staggering around like Dr Frankenstein's monster, and every step didn't leave me in acute pain.The back pain remains - but nothing like it was. Shocked, would be an apt description.6- I slept more soundly, much less disruption, less tossing & turning to adjust for pain.7- On the other hand - I'm a bit tender in my shoulders and back, from sleeping on a much, much firmer surface than ever before. I believe this is common initially, as one acclimates to the new surface and perhaps, better alignment.8- Low, unobjectionable odor. It's fine. It smells like a new mattress topper. The dog is ok with it, though he initially wasn't thrilled.The temperature is also fine; I'm "of a certain age", and I don't require anything to warm up any further than my internal thermometer, which seems to be stuck on "Surface of the Sun°.This is neither cooling, nor is it warm.9- I am 5'5 and no longer at my optimum fighting weight, thx to the chronic pain which prevents one from doing much. A former walker, yoga, Pilates devotee, this really grinds my gears. I am now a good deal larger than I was and while I refuse to disclose the number, it's not good. 😕 I had some concerns about It's ability to support me - but so far, it doesn't seem like this will present an issue. Relieved.10- This is a little bit petty, but it bears mentioning: The pretty, wavy pattern seen around the edges of the piece, actually covers the entire surface of it. If I had white sheets, I'd be livid, but I don't. Just be aware.That said, the zippered cover with the wavy stripes all over the show is handy and probably prevented the dog from making terrible gouges in it, so full marks for that.The price point was alright, there does seem to be sustained relief as a result of using it, I don't find it too warm or smelly, it's pretty stable, and the mattress straps are fantastic.So I think I'll keep it - but seriously, NOT the 4" of thickness as advertised, & zero plush / "being held" feeling.Which is a shame - but pales in comparison to the improvement in pain. As I said, my back is a bit tender from sleeping on a new, firm surface.Overall: Glad I got it, will continue use, and see how it goes.Get a better measurement device, though, & don't misrepresent the size.