Twin XL 4-Inch Thick 5-Pound Density Gray Gel Memory Foam Mattress Topper | Cooling Mattress Pad | Made in USA | Perfect for Dorm Beds, Guest Rooms & Back Pain Relief

This topper turned out to be a very good quality (made in USA) memory foam. It's not quite the 5lb density it is advertised as but it is near enough. It is very soft by design so if you are a back sleeper you may want to choose the 3 inch version (they also make a 2 inch)Since it was a topper alone, without a cover or other layers the facts can be checked. 4 inch Queen size topper 80X60X4=19200sq inches (converts to about 11.11 sq feet). It was delivered by Fed-Ex at exactly 50lb. I won't be to fussy with the pound or two for the box and plastic used in the packaging but you can see that 50 pounds devided by 11.11 = approx 4.5lb per sq foot, not 5. In this case since the memory foam was of such nice quality that .5lb difference is not that critical but still, honesty is the best policy. 5.3lb density is the relativly new industry standard for good quality memory foam. There seems to be a good deal of confusion about just what that means. Looks like most people are assuming that the higher the density the firmer the mattress or topper, but this is not necessarily the case. The ILD (indentation load deflection) measures the firmness and is determined by the vico-elastic formulation (recipe as it were). You can have 4lb and 5lb density foam, both with the same ILD measurment (same firmness), however, the 5lb having a higher density will tend to last longer. 5.3lb is the the happy medium between comfort and product longevity that has been determined through trial and error over the years by the foam industry.At 4.5lb density this topper still qualifies as a very fine product and is worthy of your attention. I hope this US company will expand thier product line to include 5.3lb density foam and perhaps 2 or 3 ILD types (Soft, Med, Firm).A word of advice. Stay away from memory foam that is made in China8/3/17 Update: BEWAREWas time to renew my topper, all foam products breakdown over time. - BEWARE, the topper currently shipping is NOT the same as in the past. I purchased my first 4" topper in 2012 and two 3" versions in the years between then and 2016. All previous purchases (4 in total / also purchased a 1') were the very same high quality vico elastic foam. This latest topper is a completely different product . So much so that I question if this is memory foam at all. I contacted 'All Sleep' and they were very quick to issue a Fed Ex return label. However, they have to know once you unpack one of these you will never be able to repack for shipping via Fed Ex, UPS, or PO.