The monitor can be widely applied in AC 80-300V mains measurement, such as office, factory, laboratory, household, and so on. You can use this item in RV to view voltage and help prevent issues with appliances. You can use this item to monitor the voltage of other appliances; when the volt gauge displays too high or too low voltage, you can selectively turn off your appliances or equipment to help prolong their life. Available Range: Widely used in AC 80-300V mains measurement. It allows you to plug into RV systems to monitor voltage and help prevent appliance issues. Keep children away from the product. Avoid using the product in damp environments. Potentiometer Adjustment: Use a screwdriver to open the outer cover, then adjust the potentiometer with a small screwdriver. Turn the potentiometer counterclockwise if the voltage is excessive; turn it clockwise if the display voltage is too low. Measuring accuracy: +/-1.5%, +/-2 digits Measuring range: AC 80 - 300V (110V, 220V) Power consumption: less than 1W (approximately 1 kilowatt-hour every 1200 hours) Number of digits: 3 Plug Type: EU Plug, suitable for use in Indonesia, Germany, France, Italy, and other compatible regions Material: ABS Color: White Package Contents: 3 x Voltage test meters Note: The package includes only the items listed above. Other products are not included. Lighting and display differences may cause slight variations in the color of the item shown in the picture compared to the actual product. Measurement error allowance is +/- 1-3 cm.