round tube is much smaller than it appears sitting spot below  that is very smalll this is for a small cat mine is only 10lbs and really can not use most of it wish i had kept the box longer i would have returned it  leson learned do not buy it if you do not see it in person .                             to put it together then have to take it apart pack it back up to return not worth the time or aggration wish i had passed on this purchase  .