Nature's Miracle - Self Cleaning Litter Box Multi Cat . Multi-Cat Self Cleaning Litter Box. Multi-Cat size that holds 40% more litter then single cat box. Large enough for cats over 15lbs or Multi-Cat households. Classic series automatic litter-box technology with antimicrobial and non-stick plastic protection. Eliminates the chore of daily scooping. Features - Carpeted Ramp, Programmable Sleep Timer, Battery back-up, Removable automatic rake and removable litter tray.