1kV – 40kV Multi-Range Voltage Detector w/Lighted Dial. The lighted-dial option sets this unit apart from features standard on Multi-Range Voltage Detector (MRVD) C403-0979. Powered by the unit’s internal battery (included), a long-life bulb gives a glow to the meter face so the scale is easy to read in most conditions. To conserve the battery, a special switch locks the light off when not in use. Its spring-loaded toggle must be pulled up to move it over the stop between its on and off positions. This helps keep the switch from being flipped on accidentally while the unit is not in use. To confirm that a line is de-energized prior to performing maintenance on it, the MRVD presents field practicality. Actually a field intensity meter, the MRVD is calibrated to read approximate line-to-line voltage when connected to any phase conductor.