It's a clever design, shipping in its least volume. The top two steps get zipped in at the use point, which shows how cover is easily removed for washing.  Additionally, that construction with zippers in their respective positions insure a tight, tidy assembly, as compared to similar others, which look baggy & irregular in comparison.  It's light and soft to touch, but supports the dogs fine.  Very easy to move around, if necessary.  The dogs approve.