Power Source Battery Powered Style Digital Color 1 Measurement Type Electrical Tester About this item Premium Quality:- High hardness chrome vanadium steel material has good conductivity, main board professionally improve chip control program, higher security and service life longer Multi-function:- Multi-functions such as zero fire wire discrimination, wire break point detection, wire on-off detection, battery self-test, etc.< /p> Wire Identification and Accurate Search:- Put your hand on the cap and touch the pole, insert the voltage measuring pen into the air, the electric pen lights up with two-color lights red and green is the live wire, lights up the green light for the zero line. Battery self-inspection:- After the battery is installed in the screwdriver electric pen, a self - inspection is required. If the green light is on, the battery is fully charged, and the battery is low if the light is off or low. Compact and Portable:- The test pen is small, light and easy to carry , the clip design is convenient for electricians for maintenance.