1. Class 0 lamps: lamps that only rely on basic insulation to prevent electric shock protection. In case of failure of basic insulation, they can only rely on the environment to provide reliable protection.
 
2. Class Ι lamps: not only rely on basic insulation to prevent electric shock, but also additional safety protection measures (grounding), and the conductive parts that are touched are fixedly connected to the grounding wire, so when the basic insulation fails, it can be touched. Conductive parts also do not become charged bodies.

3. Type Π lamps: not only rely on basic insulation to prevent electric shock, but also have safety protection measures such as double insulation or reinforced insulation to provide reliable protection

4. Class Ш lamps: rely on the supply of safe low voltage (SELV) to prevent the danger of electric shock, and the lighting equipment will not generate higher than safe ultra-low voltage (below 50V). At present, Class I lamps and Class Π lamps are the majority in the domestic market. Generally, we do not agree with the use of Class 0 lamps, and Class Ш lamps are rarely seen in the market due to their difficult technical control.