Electric current tester penThis is the perfect addition to your kit with our responsive electrical tester pen. MAIN FEATURES SafeHigh quality Our tester pen is composed of high quality and durable Drop proof insulation, ABS, 45 steel, which ensure the safety while using Self Check Function In self check before use, please hold the pen tip with one hand and touch the tail with the other hand. When the light is on, it means the tester pen is normal and has sufficient power. No