FELIWAY OPTIMUM Recharge Description Solution for relieving common signs of stress in cats, for increased peace of mind. New generation pheromones for increased effectiveness. How to use Easy to use, simply plug into a standard electrical outlet in your cats favorite room. For best results, keep the diffuser plugged in 24/7. Replace the refill approximately every 30 days: each refill lasts approximately 30 days (48 ml). Each diffuser covers an area of ​​approximately 70 m2 . warnings Avoid placing the speaker under shelves, behind doors or curtains, or behind furniture, as this will prevent it from working properly. Format 48 ml refill