Just wanted to share a little info. Having now five cats I was looking for bigger litter boxes. I didn't like the universal size especially being I have a cat that likes to dance in them and fling litter to her little hearts content. I looked at pet stores and the closest I came to the size I was looking for was $30. and came with a cover that my cats despise. I had a hard time justifying paying $120. for 4 boxes. One day at Wal-mart I came across for $3.00 the most ideal box. They are made by Rubbermaid and are 31qt. size. They can be found in the container dept. they come with lids but perhaps maybe can be used as an ideal serving tray :lol: Just wanted to share this find these boxes have worked fantastically and I saved $108.00~ How perfect is that!!