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 monitor voltage and help prevent issues with appliances. It can be used 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: Suitable for AC 80-300V mains measurement. Enables connection to RV for voltage monitoring to help protect appliances. Safety Notice: Keep children away from the product. Do not use the product in damp environments. Potentiometer Adjustment: Use a screwdriver to open the outer cover, then adjust the potentiometer with a small screwdriver. Turn counter-clockwise if the displayed voltage is too high, and clockwise if the displayed 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) Display Digits: 3 digits Plug Type: EU Plug, compatible with countries such as Indonesia, Germany, France, Italy, and others Material: ABS Color: White Package Contents: 3 x Voltage Test Meters Note: Other items not included. Lighting and display differences may cause slight color variation between the image and the actual product. Measurement error allowed: +/- 1-3cm.