A mains tester screwdriver is used to test circuits and electrical connections to see if they are live as well as being used as a screwdriver to fasten or loosen screws. They can test for the presence of live currents, so the user knows whether a circuit is safe to work on.
Voltage tester screwdriver
Some voltage tester screwdrivers can detect voltages up to 1000V making them ideal for use in high-power systems. They have features such as an ergonomic designed VDE approved handle and a neon light that lights up when the tip of the screwdriver comes into contact with a live voltage in a circuit.