We bought this mattress based on price and reviews. The twin size for a day bed. We had a guest coming to stay for a few weeks. The mattress arrived quickly and came in a roll. Bounced back to a normal mattress in moments. It definitely WAS NOT 12”!!! That part was frustrating. If the mattress is 10 inches advertise it as 10 inches! The mattress did have a bit of a industrial plastic smell. A little fabric freshener fixed that. Our guest said the mattress was comfortable and nice to sleep on. Over all I was pleased. Just be honest about the size! Roughly 10 inches!