When you’re working on electrical or DIY projects, you need a tester that won’t let you down. The Silverline Mains Tester will alert you to the presence of any live electricity in a circuit when you are looking to fix an electrical issue. The neon indicator in the top of the plastic handle lights up when the screwdriver is touched on voltages between 110 - 250V. Earth contact is achieved by touching the metal stud. Hold the screwdriver by the plastic insulating sleeve on the screwdriver blade as this provides protection against live currents.