Dr. Elsey?s premium ultra clumping cat litter has superior odor control and is perfect for multi-cat families and those cat owners with sifting or mechanical litter boxes. Ultra?s unique formulation combines heavier non-tracking granules with medium grain clay. The result is an excellent clumping litter that prevents moisture from reaching the bottom of the litter box, while providing a clump that will not break apart. Ultra controls odor naturally without perfumes or deodorants.