I got this to replace a worn out cotton mattress that came with the futon. It is not as thick as I had hoped. It’s definitely not 8 inches thick. It is 6 inches thick. It was difficult to determine exactly what it is made of. It’s listed as polyester. But that is clearly not true. I spoke with one representative who looked at some other sources online that sell the same mattress, and I had done the same, and found it to be a “bonded leather” which is a leather bonded to polyester. However, when I called to order it, the rep called the supplier who said it is a faux leather made of polyester. Which still tells me, essentially, nothing. It could be vinyl, it could be polyurethane, it could be cheap leather.  No one seems to know. It’s decent for the price and reasonably comfortable to sit on. I think it will be reasonably comfortable to sleep on as well.