Feliway Classic Refills, for use with Feliway Classic Diffuser, are a clinically proven solution to help comfort and reassure your cat at home. The continuous effect helps cats and kittens adjust to changes in their environment, feel comfortable in a new home and avoid unwanted behaviours like urine spraying, scratching and hiding. Plug the diffuser and refill in right side up in an open area where your cat spends the most time. Keep plugged in continuously and replace refills every 30 days. Replace the diffuser device every 6 months. Each diffuser and refill covers up to 750 square feet. Best results are typically seen after 3 to 4 weeks of continuous use. Use only Feliway Refills with Feliway Diffusers.