The Omega Paw Self-Cleaning Litter Box is ideal for big cats or multiple cat households. It quickly self cleans while controling dusting and odor. Simply roll the litter box to the right until the top touches the floor. Then roll it back to the upright position. The internal mechanism deposits the clumped waste into the pull out waste tray for easy disposal. The system only works with clumping litter. The clumped litter is separated from the clean litter so that clean litter is not thrown away. The covered pan design provides your cat privacy. This litter box will save you money with no more scoops, liners or filters to buy.