The Popur S7 is the best litter robot I’ve ever had. I tried the Litter Robot, and the Neakasa. Everything else has a design flaw in that the litter smells as it accumulates. My cat is such a princess that when she smells it too she will go elsewhere and pee on top of clothes, etc. She finally stopped doing that with the Popur S7 because it stores and seals the used litter separately. Genius.