Sentry Good Behavior Pheromone Collars are activated by the dogs body heat. The collar releases pheromones over 4 weeks, making it an ideal way for owners to help control stress related behavior as well as to help socialize the animal with other dogs. The Sentry HC Collar has the same technology available as a diffuser or spray, and goes wherever your dog goes, making the treatment more consistent. Soothing lavender and chamomile fragrance. Directions: Place collar around pet’s neck, adjust to fit dog’s neck comfortably. The collar must be worn loosely to allow for growth of the pet and to permit the collar to move about the neck. Generally, a properly fitted collar is one that when fastened, will snugly slide over pet’s head. Leave 2 or 3 inches for extra adjustment. Cut off the excess portion of the collar. The collar is designed to release powder when applied, which will activate the pheromones. When fresh collars are stretched out they show an excess of powder. This powder is primarily a carrier for the pheromones and not the pheromones themselves. This powder is not harmful to animals. Wash hands after placing collar on pet. The effects of one collar last up to 30 days. Seal collar in plastic bag when not in use to prolong the effect.