Convenient customs clearance is a kind of preferential measures for customs clearance, which is mainly applicable to the production of large-scale high-tech enterprises, and provides them with convenient measures such as early customs clearance, guaranteed release, expedited customs clearance and door-to-door inspection and release. The scanner gun is a device used for barcode scanning, which converts barcode images into electrical signals through optical principles, then processes the electrical signals and finally displays the results on the screen or transmits them to the computer. Scanning guns are widely used in retail, logistics, medical and other industries for tracking goods, express parcels and other information.