Function: It is used to safely check for the presence of AC voltage in outlets, light fixtures, or wires.
Visual Indicator: The handle is transparent and contains a small neon lamp that glows when the tip touches a live (hot) wire while you are grounded (by touching the metal cap at the top of the handle).
Voltage Range: These common testers typically detect voltages between 100V and 250V AC, though some models vary.
Dual-Purpose: It can also function as a standard flat-head screwdriver for light tasks.