2 sealed Boxes Feliway Optimum Diffuser 2pack total refills 4 in this listing Both EXP. 2026 These are just refills and go with the diffuser ( not included) FELIWAY Optimum is a new pheromone discovery, and the best FELIWAY answer to reduce the most common signs of stress. This diffuser can reduce scratching, urine spraying, tension and conflicts between cats, fears, and reactions to changes.