This is a great pet carrier.  I love the different features.  Especially the car seat feature.  My cats all love sitting in it.  I have only used it once so far but I love it.  
It is smaller than I expected.  It is great for our smaller cats.  Our largest cat is 11 pounds and she fits but doesn't have any room to spare. It is the extra small and I guess I thought it was the next size up.   Over all it is great!