Comfort Zone Plug-In with Feliway (mimics the feline facial pheromone) for cats and Comfort Zone Plug-In with D.A.P. (mimics the natural pheromone released by lactating female dogs to calm their puppies) for dogs relieve stress by stimulating naturally occurring pheromones that calm and reassure them in stressful situations. For cats it reduces or completely stop urine marking, vertical scratching, loss of appetite, reduced desire to play or interact. For dogs it reduces or completely stops barking, urination and defecation, whimpering and whining, anxiety and chewing. It helps both pets in stressful situations such as being alone, visitors at the house, new pets or family members, moving, vet visits, new environments, thunderstorms and fireworks. The kit contains one plug-in and one 48 ml bottle to cover 500 to 650 sq. feet. The refill contains one 48 ml bottle. One vial lasts approximately four weeks.