How Does an Anti-Theft Device Work?

You’ve seen those tags stuck to clothes in stores — they’re actually anti-theft devices. So how do they work? They’ve got two main parts: a grooved pin and a plastic casing. The pin goes through the clothing and into the casing. Inside, it slides through a set of tiny ball bearings, and a spring pushes down, locking them into those grooves. They’re almost impossible to pull apart. Some even have ink capsules that'll explode and ruin the item. To unlock it, stores use a strong magnet that lifts the inner piece just enough for the balls to loosen up so the pin can slide out.