As described and very firm. Buyers should be aware that they must be prepared to carry the bed upstairs themselves and put it together without any instructions so if you're getting an ortho bed because you have a bad back BEWARE!!
If this is basic I'd hate to read the advanced version or maybe that just reflects the nature of the subject. I'm working through slowly and it's certainly a useful book. Perhaps more of an overview at the start would have eased the way in.