1. CONDUCTIVITY TESTING TOOL This pen is designed to efficiently test the effectiveness of grounding products such as grounding pads, bed sheets, pillowcases, and wristbands. Simply place the two probes on the item to see if it conducts electricity; a light will illuminate if the material is conductive. 2. USERFRIENDLY DESIGN In just seconds, determine if your grounding product is effective without needing to plug it into a socket. This tester simplifies the process of guaranteeing your grounding items are functioning correctly. 3. INCLUDES REPLACEABLE BATTERIES Each conductivity tester comes with 3 LR41 batteries included, so you can start testing right away. When the battery runs low, easily it by removing the foot pad and cover for quick access. 4. SAFETY NOTICE This testing pen is not suitable for children under 8 years old. It is strictly for testing conductivity and should not be used on live wires or electrical equipment.