--Conductivity and Grounding Tester--The conductivity test pen can detect whether the grounding products can conduct electricity and achieve grounding. Place both probes on the product you want to test (Grounding mat, sheets, pillowcase, wristband etc.) and the light will be on if the material is conductive. Slide the tester over the surface of the grounding product to test continuity. --How It Works--When the two probes of the conductivity test pen are connected by conductive material, an electronic circuit is formed and the light will be on. So we can use it to test the grounding products if it has been successfully grounded --Easy to Use--It takes only 1 second to know if the grounding product is conductive. The grounding product being tested does not need to be plugged into a grounded outlet. If the grounding product is not conductive, it cannot be grounded even if it is plugged into the grounded outlet. --Button Cell Battery Included--3*LR41 batteries are included in the grounding tester. The test pen is ready to use when you receive it. When the batteries are exhausted, you can remove the foot pad and top cap of the pen and easily replace new ones --Attention to Safety--This test pen is not intended for use by children under the age of 8. It is only used to test the electrical conductivity of objects, and cannot be used as an electrical pen to touch live wires and equipment. --Note--The test pen will light only if the test material is conductive, even if the grounding receptacle is not connected. Conductivity and Grounding Tester：The conductivity test pen can detect whether the grounding products can conduct electricity and achieve grounding. Place both probes on the product you want to test (Grounding mat, sheets, pillowcase, wristband etc.) and the light will be on if the material is conductive. Slide the tester over the surface of the grounding product to test continuity.