The correct answer is Meter. A meter (voltmeter, ammeter, ohmmeter, or multimeter) is an instrument that displays an electrical quantity as a numeric value. Meters measure voltage, current, resistance, or other electrical parameters and show the result as a number on a digital display or analog scale. For amateur radio operators, meters are essential tools for troubleshooting, testing equipment, measuring power supply voltages, checking circuit operation, and verifying component values. Digital multimeters are the most common type, displaying measurements as numeric values on an LCD screen. Understanding how to use meters is fundamental to electronics work and equipment maintenance.