Don't waste your money
I bought this litter tray as I have two cats that stay in a lot and I was tired of constantly shovelling used litter and getting dust everywhere. This invention sounded like a great idea. However, even though it looked a bit of an eye sore in my kitchen, I found that the grate inside kept coming apart every time I rolled it over so I ended up with a 'jug' full of litter and not just the used stuff, plus the clumps of urine stayed stuck to the bottom of the litter tray itself most of the time and didn't empty so I was constantly having to remove the top to clean it out manually which kind of defeats the object. I tried all sorts of clumping litter too but to no avail. I've now thrown it away out of sheer frustration in favour of purchasing an ordinary litter tray which looks better, the cats like it better and I use low dust, bio-degradable, clumping litter so I like it better too. I'd say don't waste your money on this litter tray as it simply doesn't work.