Premium Quality - High hardness chrome vanadium steel material has good conductivity, the main board professionally improves chip control, higher security and longer service life Multifunction - Multifunctions such as zero fire wire, wire break point detection, wire on-off detection, battery self-test, etc. Wire identification and precise search - Put your hand on the cap and touch the pole, insert the voltage measure into the air, the electric pen lights up with red and green two-color lights, it is live wire, lights up the green light for the zero line . Self-battery - After the battery is installed in the electric screwdriver pen, self-inspection is necessary. If the green light is on, the battery is fully charged and the battery is low if the light is off or dim. Compact and portable - The test is small, light and easy to carry, the clip design is convenient for electricians for maintenance.