The Petmate Booda Clean Step Cat Litter Box Dome Replacement Charcoal Litter Box Filter is a large and durable filter that helps reduce and absorb unwanted odors in your litter box area for up to 3 months. Made of zeolite and charcoal, the particles in this filter are designed to trap odor molecules. The filter is easy to load and is nontoxic and safe to use. With its large size and multiple uses, this filter is perfect for any cat owner who wants to keep their home smelling fresh and clean.