This mattress works well for my guest room. It’s very firm which is what I was looking for. However, it’s definitely not 12 inches. It’s been a few days and the height of this mattress comes in around 10 inches. I attached a photo for reference. If you are wanting a true 12 inch mattress this will not work for you. Definitely false advertising especially when shopping according to the height of the mattress you typically pay more the higher the mattress is. I’m not in the mood to send this back so I guess I’m stuck with a 10 inch mattress versus the 12 I ordered and expected to get.