Abstract: A security device for preventing the theft of merchandise or other articles that provides for a closed loop system that is self-shunting without the need for removable shunt plugs. The preferred device comprises a plurality of jacks attached to a circuit board for receiving connector plug assemblies that are operatively connected to the articles through sensors. When the connector plug assemblies are not within a jack, a jack contact will engage a nail contact to close a circuit, thereby shunting the jack. Insertion of the connector plug assembly will deflect the jack contact away from the nail contact and create a second closed loop indicating that the jack is in use, and which will monitor and warn of any tampering with the sensor on the article.