Feliway Friends Diffuser is designed and clinically proven to help minimise and even outright prevent fighting and tension between household cats. If your cats are frequently fighting with each other, hissing, growling, or spitting, or hiding from each other, Feliway Friends may help to reduce these signs of conflict.By replicating the cat appeasing pheromone (CAP) which is naturally produced by the mother after giving birth to nurture a bond between her and her kittens, Feliway Friends uses the same effect in your home to help your feline flatmates live together more harmoniously.Each diffuser refill lasts up to one month.