A theft detection device configured to be coupled to a merchandise product, the theft detection device comprising: a housing with a first end of an electrically conductive strap attached to the housing; a light sensor disposed within the housing, the light sensor configured to sense the amount of light shining on the theft detection device; a motion sensor disposed within the housing, the motion sensor configured to sense movement of the theft detection device; an emitter disposed within the housing, the emitter configured to provide audio signals to a user; a microcontroller disposed within the housing, and coupled to the light sensor, motion sensor, and emitter, the microcontroller configured to control the emitter to emit an alarm signal based on data from the light and motion sensors, the microcontroller further configured to cause the emitter to emit an alarm signal, when the conductive strap is cut or loosened from the merchandise product, characterized in that the housing has an opening for a second free end of the conductive strap, configured to wrap securely around the product being protected and returned back to the merchandise tag where it is inserted through the opening, wherein the theft detection device is activated when the second end of the conductive strap is inserted into the opening, wherein the conductive strap includes a plurality of gears along a length of the conductive strap, the plurality of gears configured to engage a mating gear set on a movable metal gear to lock the conductive strap in a fixed position and characterized in that the theft detection device further comprises an installation switch which is closed when the conductive strap is inserted into the opening and wherein the said installation switch comprises a first metal contact and a movable metal gear configured to engage the conductive strap to cause the conductive strap to come into electrical contact with the first metal contact. a housing with a first end of an electrically conductive strap attached to the housing; a light sensor disposed within the housing, the light sensor configured to sense the amount of light shining on the theft detection device; a motion sensor disposed within the housing, the motion sensor configured to sense movement of the theft detection device; an emitter disposed within the housing, the emitter configured to provide audio signals to a user; a microcontroller disposed within the housing, and coupled to the light sensor, motion sensor, and emitter, the microcontroller configured to control the emitter to emit an alarm signal based on data from the light and motion sensors, the microcontroller further configured to cause the emitter to emit an alarm signal, when the conductive strap is cut or loosened from the merchandise product, characterized in that the housing has an opening for a second free end of the conductive strap, configured to wrap securely around the product being protected and returned back to the merchandise tag where it is inserted through the opening, wherein the theft detection device is activated when the second end of the conductive strap is inserted into the opening, wherein the conductive strap includes a plurality of gears along a length of the conductive strap, the plurality of gears configured to engage a mating gear set on a movable metal gear to lock the conductive strap in a fixed position and characterized in that the theft detection device further comprises an installation switch which is closed when the conductive strap is inserted into the opening and wherein the said installation switch comprises a first metal contact and a movable metal gear configured to engage the conductive strap to cause the conductive strap to come into electrical contact with the first metal contact.