Pheromone technology is proven to modify stress behavior such as: inappropriate marking, excessive barking and chewing. Lasts up to 30 days. Lavender chamomile fragrance. Sentry calming diffuser for dogs helps with the following stressful situations: Separation anxiety. Thunderstorms. Fireworks. Noise fears. Visitors. Holiday stress. New baby. New pet. How does it work? Sentry calming diffusers for dogs help in fearful or stressful situations. Calming diffusers for dogs mimic the pheromone that the mother dog produces to calm and reassure her puppies. Dogs recognize these pheromones throughout life. It mimics the natural way to help dogs cope with new and fearful situations. The lavender and chamomile provide a soothing fragrance. Directions for Use: Plug in the diffuser to any electrical outlet to release calming pheromones that will lessen the anxiety and stress related behaviors of your dog. Replace bottle with sentry calming diffuser refill for dogs every 30 days and the diffuser every 6 months.