SENTRY Calming Collar for Dogs, Up to 23-Inch Neck, Includes Three Dog Calming Collars, Lavender Chamomile FragranceSENTRY Calming Collars use patented GOOD Behavior pheromone technology. Using a pheromone that mimics the one mother dogs produce to calm their puppies, the collars are clinically proven to reduce or eliminate stress related behavior such as inappropriate marking, excessive barking and chewing. Collars help alleviate problem behaviors triggered by travel, thunderstorms, fireworks, being left alone and new social situations. This collar continues to