Feliway is a synthetic copy of the feline facial pheromone, used by cats to mark their territory as safe and secure. By mimicking the cat's natural facial pheromones, Feliway creates a state of familiarity and security in the cat's local environment. As a result, Feliway can be used to help comfort and reassure cats, while they cope with a challenging situation and/or help prevent or reduce the stress caused to a cat during a change in their environment. Diffuser lasts about 4 weeks.