Help reduce stress-related behavior at home with the Sentry Calming Diffuser Refill for Cats. This refill bottle is designed for use with the Sentry Calming Diffuser for Cats (sold separately). No collars, no sprays—simply plug the diffuser into an electrical outlet. The diffuser releases a calming pheromone to help reduce stress-related behaviors caused by stressful events like loud noises, visitors, and introducing a new pet into your family. Plus, it’s safe for cats of all ages and breeds, making at-home support simple.