Arm & Hammer Universal Litter Filter for Hooded Cat Litter PansThis litter pan filter is designed to fit both the large and jumbo sized Arm & Hammer Hooded Litter Pans. All you have to do is install the filter in the filter slot on your litter pan"s hood and enjoy less feces and urine odor in your home for up to 3 months. The Arm & Hammer Universal Litter Filter for Hooded Cat Litter Pans uses dual odor absorbers to help control cat litter odors.