At present, there are a variety of supermarket anti-theft buckles, different frequencies, different shapes and different unlocking principles, in the end how to distinguish and choose the corresponding unlocking device, today to give you a brief introduction.Conventional anti-theft buckle is mainly composed of lock core and magnetic bar, the principle of unlocking is also very simple, three magnetic beads stuck fixed steel nail, when the raised part of the magnetic buckle into the groove of the unlocking device, three magnetic beads separated, the nail is removed.Different magnetic clasp, lock inside the size of the magnetic force are also different, so the trip required device the size of the magnetic force is different also, general magnetic size in the 4500-16000 gs and principle of a special type of guard against theft clasp trip is not magnetic, but a spring chip stuck, this depends on the magnetic tripping device can’t open, this kind of guard against theft clasp is generally oblong shape,There’s a hole on the top side, and when you release, a hook on the release goes deep into the hole, pushes the spring back up, and the nail comes off.