If cat litter box odors are a problem in your home. Van Ness's Zeolite Air Filters are the solution. Our Zeolite filters fit all Van Ness enclosed litter pans. Only the Pure Ness Air Filter offers a real solution to cat odors, zeolite. Zeolite is a natural mineral which actually removes ammonia odors from the air. In our patented system of air purification, zeolite-coated filter pads soak up ammonia gas on contact. Enjoy true odor control with the Pure Ness Air Filter, the all natural ammonia remover that absorbs urine odor before it leaves the litter box.