Update: after sleeping in this, it’s hard as a rock, I don’t understand why same mattresses different dimensions are such different size. Having purchased different bed size and thickness I thought I would give a review to help others. Originally I purchased 8” green tea mattress. Loved, and very comfortable. So I ordered a twin sleep ultimate 8” zinus also very comfortable. So then I ordered the zinus short queen 6”, major fail! Very uncomfortable, didn’t rise fully. Then I added a 2.5 topper, still very uncomfortable. So I ordered a full size mattress zinus green tea to replace the 6” and thank goodness this ones comfy! I was nervous. Overall I love zinus. I have 3 mattresses which I love. I would recommend going no thinner than 8” I would of loved it I get the 12” but wasn’t in my budget. But honestly the 8” in the green tea model and the sleep Ultima model are very comfortable. Hope this helps!