Say goodbye to another chore in the litter tray. The Litter-Robot 4 LitterHopper® does the job of refilling the litter tray optimally so you don't have to, whether you're at home or away. The LitterHopper® automatically fills the Litter-Robot 4 with fresh cat litter and ensures that the litter is always optimal for your cat. Gain back time and enjoy extra convenience with this hands-free litter refill solution. Automatically dispenses litter into the ball when needed Maintains recommended litter level Holds up to 13 cups of litter Compatible with various litter types, including clay and silica* New bonnet included (Litter-Robot 4 not included) Installation required *Litter-Robot sold separately