Fantastic fit on my full sized 10" hybrid mattress. No problems getting it on, at all. Super easy. My mattress is a little firm for my preference so I was looking at adding a pad (and actively shopping for) when I saw this. It looked interesting- cooling, adds some loft and softness, fits deep mattresses, attractive. And not over priced at $27Figured it was worth giving a try.It fits my full sized bed really well. The elastic is thick and does a great job grabbing the underside of the mattress. I am suspect that it would fit a 21" (maybe 12", likely pushing it at 14") mattress, as the elastic just goes under my mattress. But whatever, it fits mine very well and stays put. It was easy to put on and take off (and put on again).I love the teal color, and the overall look. I almost don't want to cover it up as I really like how it looks with nothing else on it. It is kind of giving me ideas for another bed if I see a color that could work.It doesn't provide much of a plush padded feeling. But it does give just a light level of pleasantness. However, it isn't enough so I went and ordered a thicker pad. But I am pleased to have purchased it, and I imagine it will work well with the pad (haven't got it yet). EDIT: what a dream! It works really well over a mattress pad, and the combo is better than either one used alone.Doesn't exactly have a cooling effect, yet it seems to be able to disperse heat more evenly. Like my torso isn't hot when I sleep, but it isn't exactly cool. I think the main function is to keep moisture from being trapped which can make the body feel more hot. I am less hot since putting this pad on, which is a huge positive as my bed gets hot sleeping with big dogs.I think overall it is effective in making for a more comfortable bed. I DO recommend it.Oh one little detail in the packaging. I like how well it was packaged and how there was a strip of cardboard placed just under where the seams meet where one would usually take a box cutter to. If this was intentional then it was super thoughtful, as it helps to protect the mattress pad when trying to open the box.machine wash, tumble dry low.This didn't help much with making my full size bed softer as I would have hoped but I still use it. I think I should purchase a second one or maybe a mattress pad. It made my bed slightly more comfortable but I think it is still a good find if you want something to make the bed softer.I bought this for my teenage daughter who doesn't like to use sheets. It is so comfortable, a beautiful color, and stays on the bed better than any mattress pad I've tried.Great purchase.... they are really thick and comfortable- fits the twin beds like a glove!This added enough softness to be comfortable and still give support.Overall it worked great to cool the topper heat. It is like a regular mattress feel now. Cover is soft and thick enough to disburse body heat. Very happy and looked at may options with mixed reviews. Definitely cooler than before and would recommend it!It's not too bulky, the comfort is perfectIt helped me on some of the painKind of flat but notice it underneath. Just like you have many layers of sheets. It is basically thin layers of plastic with billions of tiny holes. When it is made for cloth, the air gets through the fabric easy and dries it quickly when you feel cool. But when you lay on it with your weight for some time, the heat builds up because new air can't get in and the heat can't escape. We don't move that much during sleep. I didn't feel it cooler than usual but hotter. But it is the best mattress protector I have ever had if you don't have a problem with the heat during summer.Comfy enough, but nothing special about it.