an animal training device and system which uses a voltage to frequency conversion technology providing the capability to adjust in gradual incremental levels upward and downward for consistent and individual electronic control of separate output to an animal undergoing training to learn new behaviors which are desired by its owner / handler / trainer . the device is contained in a housing which is worn around the neck of an animal by means of a collar strap or attached to a harness that properly fits onto an animal . the primary use is with dogs , but all kinds of domestic animals may be trained using this device . this vfc technology is offered in a variety of electronic platforms . whether one - way or two - way remote controller with manual activation by the user , automatic activation by remote sensor detectors , or automatically activated by an on - board microprocessor circuitry sensing the animals own actions , either or all device outputs allow the animal &# 39 ; s caretaker the unique capability to select an appropriate level of one of a variety of cue signals at a given moment allowing the animal not to be overwhelmed or to cause any over - reactions .