Booda Litter Box Charcoal Filters Dome, 2 Pack, 12 Pack Traps both urine & feces odors using a combination of charcoal and zeolite particles. Activated charcoal is able to absorb and trap the odor by chemically binding to it. Zeolite has a cage-like structure and works with the charcoal to trap odor molecules for dual protection from unwanted odors. Minimizes cat box odors so you home smells clean and fresh. Each pack contains 2 filters. 1 filter will absorb unwanted odors for up to 3 months. Keeps air clean for 6 months with 1 pack of filters. Nontoxic and easy to load so you'll have more time to spend with your furry friend.