I tried ScoopFree Classic Self-Cleaning Litter Box and being we have 4 cats one being a kitten, it saves me from scooping the cats waste. The PetSafe ScoopFree Self Cleaning Litter Box does all the work for you.

They come with a Self Cleaning tray that you slide in and turn on. It runs on AC power, The box itself measures 27.6 X 19.1 X 6.2 inches about the size of a large litter box.

There are two small sensors that detect when your cat is in the box. It waits about 20vminutes after your cat has finished before it starts the raking process. It starts at one end and slowly moves to the other side, pushing the waste in front. When it gets to otherside a trap door opens, and the rake pushes it inside and returns to original position. Easy peasy....its sorta fun to watch, and I dont have to scoop the cats waste.

Its a does its job for sure and when its full or about 25 days.