Got my mattress from knoxfoam.com. They are great for boat cushions and can cut anything anysize you want. TIP...Grade B is the best to get for campers, boat cushions, mattresses or whatever your needs for foam. They also will make the custom covers for your mattress. I'll get mine later. I was able to change my order from a 4" to a 6" thick mattress before they turned in my order. Much better for us older folks and for the wife too. The 6" was recommended way over the 4 or 5" not only by Charity at Knox Foam but by our doctors as well. 4" is ok if you are young and spry which I ain't!