1SELF TEST FUNCTION: Electrical tester can be used for neutral fire line judgment, line open and closed detection, with self test function. 2TWO TESTING METHODS: Voltage tester has burst flashing tri color and beeping alarm, non contact induction and contact induction two testing methods. 3EASY TO ASSEMBLE AND DISASSEMBLE: Voltage tester pen is designed with slotted screwdriver tip, 3mm in diameter, easy to contact, assemble and disassemble. 4HIGH BRIGHTNESS LED LIGHT BEADS: Electrical tester pen built in high brightness LED light beads, transparent pen shell, testing intuitive, easier to measure. 5SAFE AND DURABLE: Voltage pen adopts intelligent motherboard chip and professionally upgraded chip control scheme, with higher safety and longer service life. 6EASY TO CARRY: Voltage detector pen adopts humanized pen clip design, which is more convenient to carry while working.