I was looking for a box with high sides, because my 2 kitties  kept making their hard deposits on the sides or behind the box, on the carpet.  This one looked pretty good, so I took a chance, and indeed the sides are so high, that I need 2 boxes of litter instead of 1.  So far, no deposits outside.  My only problem, is that it is too big to fit in my kitchen sink for washing....so I've done it in the bathtub.  I don't know yet, if it will be too heavy to carry to the bathtub, when there are two boxes of litter in it.....well, we'll see !