At first when I opened the box and saw the tray I thought there's no way this is going to work well. I was wrong! This self cleaning litter box is amazing and cheaper than others out there!!! My cats are super picky about their litter box so I wasn't sure how they would like this, when it cleaned itself it makes them jump because they aren't expecting it but they have grown used to it and enjoy having a perfectly clean litter box everytime they need to go. I changed it out after 15 days because I have 2 cats so it lasted much longer than I expected and was better than cleaning the box by hand twice a day every day!