The Taser gun first appeared in science fiction novels in the early 20th century, and some people called it the "electric shock gun" based on its principle. The Taser gun has no bullets, it relies on firing charged "darts" to subdue targets. There is a pressure magazine filled with nitrogen inside the gun. After the trigger is pulled, the high-pressure nitrogen in the cartridge clip is released rapidly, and two electrodes in the gun chamber are fired out. After hitting the target, the barb can hook the suspect's clothes, and the battery in the gun chamber releases the high-pressure through the insulated copper wire, making the criminal's muscles spasm and shrink into a ball. In order to prevent police from abusing firearms and firing indiscriminately, the Taser gun was designed with a recording function added