A shock collar or remote training collar is any of a family of training collars (also called e-collars, Ecollars, or electronic collars) that deliver electrical stimulation of varying intensity and duration to the neck of a dog (they can also be applied to other places on the dog's body, to achieve various training effects) via a radio-controlled electronic device incorporated into a dog collar. Some collar models also include a tone or vibrational setting, as an alternative to or in conjunction with the shock. Others include integration with Internet mapping capabilities and GPS to locate the dog or alert an owner of his/her whereabouts.
Originally used in the late 1960s to train hunting dogs, early collars were very high powered. Many modern versions are capable of delivering very low levels of shock. Shock collars are now readily available and have been used in a range of applications, including behavioral modification, obedience training, and pet containment, as well as military, police and service training. While similar systems are available for other animals, the most common are the collars designed for domestic dogs.