Instruction: Answer the given question using the supporting document.

Input:
Question: I want to replace the gel foam mattress my husband has been using and want to know if this one is reversible?
Document: I got one of these through insurance a little over a year ago. The warranty is only 6 months and I am half the weight. Less than 5 months after acquisition the center gel foam cells collapsed. Less than five months later the same thing happened to a replacement and a third replacement died in the same manner. The dealer said that customers had mixed experiences. I will be looking for a  memory foam topper with a much better warranty. Too bad- the gel foam tops were very comfortable while they worked.
My wife has been using her Invacare bed for a few months. Lately she had started complaining about the comfort. She weighs about 90 pounds so I was surprised. Besides being uncomfortable, something about the original mattress wasn't letting her turn over. I searched for a highly rated solution and found this overlay. She loves it! After I had installed it she wanted to check it out and instantly fell asleep. After a couple of nights she is still thrilled. I have no problem recommending this product.
My husband needs to use a hospital bed now and this turned a very uncomfortable spring mattress into a comfortable bed for him
This mattress overlay is very comfortable with no pressure points. I had been sleeping on a waterbed for the last 35 years and had no regrets when I switched for reasons of having a bed that is easy to move.
This is a great alternative to a "Gel Bed". The list price on it is $545.00! For anyone that is partially bedridden it is ideal.
I bought this as a gift to my daughter. She spends most of her time in a hospital bed, not known for comfort! She called me the following day and said it was the best nights sleep she had in months! That was all I needed to hear! !
Bought this for my father-in-law who uses a hospital bed. He is not bed -ridden; however, at his age, he spends a lot of time in bed and was uncomfortable. He is quite pleased with this mattress overlay.
color choice  very unusual, but concept is very good, and it improves the comfort of the bed quite a bit.
This has made a great improvement in my wife's comfort level. We are very pleased with it and give it an excellent rating.
Answer: I don't believe you're supposed to flip it upside down, but you can reverse the head and foot. I've used these mattresses for years and when they get an indentation , reversing it helps.