E in the lighting source refers to the model of the screw lamp head, and the number behind E represents the diameter of the screw. Commonly used are E14, E27, E40, the resolution of the lamp holder is a major equipment maintenance, because different lamp types are not the same caliber. For example, E14 is usually the lamp holder used on crystal lamps and wall lamps, which can be matched with incandescent bulbs. E27 is the most frequently used lamp holder, and the general energy-saving lamps and incandescent lamps use this lamp holder. The E40 lamp holder is relatively large and is generally used in high-power gold halide lamps.
