All I can say about this mattress is ...what a great feel. I am yet to place this on my full-sized bed..purchased from another source... However I have tested this out on the floor. I cannot wait to get the bed asembled! I think I may have purchased the last one. It says sold out now. But keep on looking for this product.I have back troubles and this feels so firm and supportive, I may have to use my guest room myself!. This mattress comes rolled up like a giant sausage in plastic wrap and then a thick, water resistant orange packaging. It appears flat and lifeless at first. However, in two days it really fulls out. The factory plasticky odour goes after 4 days. I would reccomend a water proof matress cover. It looks and feels like luxury. Get yourself one if you have back pain.I believe it will stand the test of time. I say this because I purchased a 4 inch queen sized memory foam topper for my master bedroom three years ago and that is still as firm as the day I bought it. Thank you Overstock for great products at great prices!Will measure the inches now that the mattress has come to it's full size to inform all if it is really 12 inches. It looks like it is though.