Feliway Friends Refill is a veterinary-recommended solution designed to promote harmony between cats living in the same household. This 48ml refill contains calming pheromones that help reduce tension and conflicts between cats, creating a more peaceful home environment for 30 days. This refill is specifically designed to work with the Feliway Friends diffuser unit (sold separately). It is clinically proven and recommended by veterinarians as the #1 brand for managing multi-cat household tensions. The product works by mimicking natural feline pheromones that help cats feel safe and calm around each other. For optimal results, the diffuser should be plugged in continuously in areas where cats spend the most time together.