These are great!!  They come folded up, but easily unfold and finish with putting the tops of the steps in place (the tops for the bottom two steps are folded inside the steps and the top of the top step is separate).  There are inserts to help the steps keep their shape, and they feel sturdy.  The material seems very durable.  And did I mention you can store pet toys (or whatever) inside the steps?  These are really nice!