The mark on the power tool housing indicates the double insulation mark.

Double insulation refers to insulation with both working insulation (basic insulation) and protective insulation (additional insulation). The insulation between them is the insulation used to prevent electric shock when the working insulation is damaged.

Double insulation is a basic protective measure used for Class II electrical appliances and tools to prevent electric shock, and refers to an insulating structure with both basic insulation and additional insulation. The so-called basic insulation refers to the basic protective insulation that provides protection against electric shock to live parts. The so-called additional insulation refers to the independent insulation provided in addition to the basic insulation in order to prevent electric shock when the basic insulation is damaged. The advantage of double insulation is that it is safe and reliable, and it will not cause an electric shock accident when the basic insulation is damaged.

The characteristic of double insulation is that it does not require grounding protection (and does not allow grounding protection), so it is not limited by the presence or absence of grounding facilities in the place of use, and unlike Class I tools, when there are no other safety protection measures, the user Must wear insulating gloves, wear insulating shoes or stand on insulating pads to operate. The power supply is convenient to use, unlike Class III electrical appliances and tools, which must be powered by a safety extra-low voltage to prevent the danger of electric shock, but can directly use the AC 220V power supply.