The Adaptil Diffuser is a discrete and effective plug-in which fills your home with a reproduction of the canine appeasing pheromone, a natural product proven to calm and comfort both puppies and adult dogs.The Adaptil diffuser can be used to help your puppy remain composed during training and housebreaking, as well as helping puppies and adults alike during challenging situations such as fireworks, new babies or houseguests, Christmas, and Thunderstorms. Each vial included with each diffuser lasts 30 days, with refills available; the diffuser can be refilled up to five times before needing to be replaced and should be plugged into the room where the dog spends most of its time. The Adaptil diffuser may be used alongside the Adaptil Collar or Adaptil Spray.When to use If your dog struggles to stay alone at home (house soiling, barking, whining) If your dog is afraid of sounds such as thunderstorms or fireworks If your dog gives indications of fear at home or stress when guests