Instruction: Answer the given question using the supporting document.

Input:
Question: What size mattress does it fit?
Document: I purchased this frame with the Mozaic Full Size 8-Inch Futon Mattress, Black, and i'm kicking myself in the arse for it. not the mattress, but the frame. the frame came in scratched up really badly, kinda sucked but it wasn't enough to make me return it. not even a two days after set up, the one of the two long support beams started bending. and it's only me and my fiancee.
Once we received the futon, we loved it! It fit perfectly in our room. Needless to say, we use it for overnight guests..
arrival for both mattress and frame came four days earlier than the ETA date. so i was happy about that.
yeah decided to keep it but it is on the cheap side the material does not see like it will last but we will try it still looking for  good mattress
Order came earlier than expected. was easy to assemble and looks great in my guest sitting room, sturdy, strong and feels great when I added my mattress to it.
It does its job so far, but its not verry easy to close with the mattress on it. It was pretty easy to assemble, I did it by myself and I'm a female, and not a carpenter. It's not to heavy, and its pretty sturdy. I have it on my wood floors, and it did not damage them yet. So far, so good..
i have four legs on each side, and so far the frame is well.the mattress is awesome. comfy, but not an all time comfort. we sleep on it daily (college students) it's enough for the two of us, but kinda wish i went with a thicker one. but deff recommend the mattress if your on a tight budget and plan on sleeping on it for a while.
Let me start off by saying I am not a giant man by any means(5'11 170lbs) and after a couple weeks of regular use, the bars that support the futon mattress have bent all the way to the floor making it virtually unusable. Out of the box: the pieces were banged up and the paint scraped off in places. If you want a futon that last for a couple weeks this works... otherwise get something of better quality.
Luckily this futon frame isn't one of those &#34;you get what you pay for deals&#34;. This is an affordable frame that is sturdily built and is relatively easy to put together. I bought this frame with a Mosaic 8 inch full futon mattress and the mattress fits perfectly with this frame.Yes, the instructions of assembly aren't the greatest, but common sense can help you put this together in little time.
this is some extra cheap chinese version. save yourself some $$$ and headache and get a better quality. it arrived banged up, covers for the open pipes were missing, rost dust came out everywhere on the carpet. they use the cheapest screws, if you tight them up just a little, the whole material bends. washers were so thin, i had to go to homedepot and get &#34;real&#34; washers.
Answer: I bought a Queen size mattress and it fits well