The specific manufacturing method is: lift one end of an abandoned can (such as Lulu beverage can) and beat the other end with a round hammer. Roll up two 1 batteries with thick corrugated cardboard and put them in a can, with the positive pole facing up and the negative pole facing down. Find a suitable plastic cover (for example, the magic big roll cover can just be buckled on Lulu's beverage can), and dig a round hole in the center of the cover, the size of which is suitable for the light bulb to be inserted tightly. Insert the bulb base into the small hole. Take a section of tracing wire, peel off the wire skin at both ends, wrap one end around the lamp cap, and tie a small hole at the other end from the side of the plastic cover. Put the plastic cover on the jar. Check whether the bulb and battery are in close contact. Disposable flashlights will be ready here. When in use, press the wire on the side wall with your thumb on the unpainted weld away from the can, and the flashlight will glow. When your thumb jumps off the wire, the flashlight will go out, which is very convenient to use.