Posted by a reviewer on Amazon

It says that it takes up to 2 days to expand but it seemed like it was instantly the correct size

Posted by a reviewer on Amazon

The worst experience is that the bed moves on the sleep master smartbase mattress frame we ordered

Posted by a reviewer on Amazon

Was full size 68 hours after coming out of box

Posted by a reviewer on Amazon

It is not super firm

Posted by a reviewer on Amazon

So having bought a brand new posturpedic that claimed to be medium firm i was loathe to get yet another mattress for the 2nd bedroom but had no choice

Posted by a reviewer on Amazon

The mattress arrived without the usual amazon packing slip and return instructions

Posted by a reviewer on Amazon

Once released from the packing materials the mattress expands to its full size and it would be impossible to compress it back

Posted by a reviewer on Amazon

Food for thought in case youre thinking of returning it