Self-cleaning litter box features a quiet motor and anti-leak guard to protect against sideways urination. The disposable litter tray provides hands-off convenience and unbeatable odor control so you don't have to see, touch or smell messy waste. Tray has a plastic lining to create a barrier to help protect against leakage and also comes pre-filled with Premium Blue crystal litter. Premium Blue absorbs liquids and dehydrates solids to provide unbeatable odor control. The rake automatically sweeps waste into a covered compartment 20 minutes after your cat uses the litter box, and the sensor automatically re-sets the 20 minute rake timer if your cat re-enters the box. Not for use with kittens younger than six months of age ALSO COMES WITH 4 REFILL TRAYS AND HOOD!!