Innofresh Activated Charcoal Pet Odor Absorber Innofresh PET Fragrance Free odor absorbers utilizes our patented activated charcoal carbon technology to eliminate all odors. No worry about irritating or harmful fragrances for your pets or yourself. Last up to 4 Months. Fragrances just cover up odors while Innofresh PET odor absorber traps and eliminates those lingering odors from your pets. Our activated charcoal carbon odor absorbers work effectively against those tough litter box odors, as well as in areas where cats, hamsters, gerbils, pet mice, rabbits, hermit crabs, turtles, birds, reptiles, ferrets or other small animals are kept. Built in clip securely fastens to most litter boxes, and cages. The best cat odor eliminator available!