For more than a decade we?ve worked side by side with leading pet experts and top universities researching safe, effective ways to help pets lead happier, less stressful lives. SENTRY Calming Collar for Cats is scientifically proven to reduce excessive meowing, marking and scratching. This collar releases calming pheromones for your cat for 30 days. Safe and effective for use by cats of all ages and breeds. br/>Sold in Quantity of:1