The Sentry Calming Collar is ideal for using both at home and on the road. Scientifically proven to modify canine behavioral problems caused by stress or fear, this collar employs Good Behavior Pheromone Technology to prevent excessive barking, whining, chewing and marking. Created to mimic the pheromone produced by mother dogs to calm their puppies, this technology creates a soothing, anxiety-free atmosphere for dogs that struggle with everything from separation issues and traveling anxieties, to fear of fireworks and thunderstorms. Fits up to a 28" neck. Each collar continues to prevent stress for 30 days. Imported.