What Is That Thing?

Recently I purchased a Dremel® power tool and noticed a black plastic device mounted on the power cord. On this device the words “Do Not Remove” were prominently displayed.  This piqued my curiosity, so I search the web for the “Emtag” and “Do Not Remove” and found numerous results.  Most of which gave confusing information about this device.  Some said it was to suppress high frequency interference in electronic circuits.  Some said it was a tracking device.

Emtag picture
Emtag Side A
Emtag Side B
Emtag Side B
Emtag removed pic
Emtag Removed

Not being able to live with this information void, I decided to try a test, contrary to all warnings and remove the device!  I just used pliers to squeeze the device until it separated into two pieces.

The Dremel still ran!  But was I now interfering with my wireless network while grinding, shaping and polishing?  Looking at the inside of the removed Emtag™, I saw something familiar.  This flat white plastic tag (seen in the picture Emtag Removed) is commonly used in stores to prevent theft.

Emtag™ is a anti-shoplifting device that is attached to electrical product cords using electronic article surveillance (EAS) to prevent theft. The Emtag™ device is manufactured by B&G International Inc. and contains a Sensormatic Supertag acousto-magnetic (AM) tag. These AM devices are typically attached to products and packaging during manufacturing. The devices are sensed by special antennas located at exits from a store or building. The Emtag™ comes in several sizes for attachment to power codes of different sizes.

This device can safely be removed (after purchase) from power tools without affecting the performance of the tool.  This device has nothing to do with suppressing high frequency noise in electronic circuits like ferrite rings.  In fact, it is similar to those mattress tags that say “Do Not Remove” in that they are unneeded after you get your purchase home.