Many types of litter boxes and litter materials are available to cat owners. Litter boxes or pans are generally rectangular plastic containers. The box size should be large enough to comfortably accommodate an adult cat. The sides of the pan should be low enough for easy access by a kitten or an ailing adult cat. Covered litter boxes are available in a variety of styles and may substantially reduce odors.
Some litter covers have charcoal filters that further reduce odor.
You can purchase a litter pan without a cover, but ask whether a cover may be added later, just in case. A standard covered box requires the cat to step into an opening in the cover's front. Other models require the cat to enter and exit through an elevated opening. The top portion of a covered box can also be removed and placed upside down as an alternative litter pan for cats that tend to void over the edges or are unsteady because of age or illness. Cats are not born with an instinct to eliminate on unnatural litter filler.