Royal Pet Fresh Kitty Zeolite Litter Pan Replacement Filter The Fresh Kitty Zeolite Replacement Litter Box Filters help minimize unpleasant odors Keeps your home and litter box area smelling clean and fresh This filter is compatible with all enclosed litter pans Absorbs unpleasant odor for up to three month Includes 1 filter | Dimensions: 6.375" x 4.25"