Works like magic…but it's science! Harmony Pet Cat Calming Home Diffuser is portable, requires no plug, no batteries and no messy cords. Each Harmony Pet Home diffuser pod will calm the environment of a room for up to 750sq ft. Harmony Pet Home Diffuser for Cats will deliver calming benefits for up to 30 days and helps to reduce stress related behaviors. No plug required! Harmony Pet's calming pheromone has been clinically studied and proven to be 2.5 times more effective than leading brands in reducing stress.