Innofresh PET Fragrance Free odor absorbers utilizes activated carbon to eliminate odors and is completely fragrance free. No worry about irritating fragrances for your pets or yourself. Fragrances just cover up odors while Innofresh PET odor absorbers traps and eliminates those lingering odors from your pets. Works effectively against those tough litter box odors. Just clip-on to your cat litter box or even small animal cage to eliminate odors safely and effectively and without chemicals, gels, powders and sprays. Built in clip securely fastens to most litter boxes, cages. Don?t settle for litter that claims to control odors. Eliminate them with Innofresh activated carbon odor absorbers.