Feliway 30 Day Starter Kit Plug-In Diffuser & Refill, 48-mLFeliway is a synthetic copy of the feline facial pheromone, used by cats to mark their territory as safe and secure. By mimicking the cats 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 help prevent or reduce the stress caused by a change in their environment. Key Benefits