What's the use of the security door at the exit of RT Mart supermarket?

The main function of the supermarket exit security door is to install a radio frequency detector at the exit of the shopping mall, attach a soft label or a hard label to the goods, and decode or remove the soft label or hard label on the goods with a decoder or unlocking device when paying, so that the goods can pass through the detector at the door smoothly. Taking away goods with soft labels or hard labels without payment will trigger the detector alarm when passing through the security door detector, thus protecting the economic interests of the mall.