Halt II dog repellent has stopped attacking dogs since 1966 for the U.S. postal service and many public utility meter readers. Halt II has 285% more effective stopping ingredient than standard halt. Halt causes temporary discomfort to the attacking dog when sprayed in the face, giving you time to retreat to a safe distance. This item must ship via UPS Ground. Omark Safety can not ship this product out of the continental United States.