A security device for attachment to an article to deter theft of the article has a housing containing an alarm system including an audible alarm with a defeat mechanism having a two-part connector that attaches to both a cable and a locking mechanism. The connector includes a mechanical fuse (e.g., two-step ferrule holder) that provides defeat prevention of the alarm device. The locked device alarms if pulled too hard from twisting the cable without releasing the primary lock. The connector is preferably shaped as a generally elliptic cylindrical bayonet having an oval transverse cross-section and a truncated oblique cone-shaped distal end. This enables the plug to be inserted into a locking channel of the locking mechanism in either of two directions facilitating the locking of the attached cable about an article of merchandise. Moreover, the oval shape takes up less space than a round bayonet while providing greater strength through longer latch engagement area on the wider side of the bayonet, especially as opposed to a circular cross-section bayonet.