Feliway MultiCat is clinically proven to help reduce tension and conflict in multi-cat households. The diffuser emits a copy of the feline appeasing pheromone mother cats produce during lactation helping the multiple cats feel safer and secure in their surroundings. Cats of all ages sense this pheromone giving them a calming affect with less animosity. The diffuser covers 500 to 700 sq. feet. Kit includes plug-in diffuser and 30-day refill.