Bright & Reliable IndicationA quality bulb is built in this light tester, where provides a bright and reliable light indication, guiding you through intricate electrical tasks to the source of the problem with ease. Highly visible light indicates circuit's signal, the brightness of the light will be vary with the different measured voltages. Safe & Durable UseThis electrical tester pen adopts ergonomic handle for comfort and a safe grip. Constructed with high quality ABS body with higher transparency, shatter-proof and durable, can withstand long-term rough use. Premium insulation protective rubber tip protects you against electric shock, heat insulation and oil resistance for safe operation. Bidirectional Current Voltage TestingYou can attach the alligator clamp either to negative or positive ground, while use the probe to touch the other side to diagnose short circuit or defective fuse. Its lightweight and easy to carry, will not take up much space in your toolbox or storage area, co