1.Wide Measuring Range: DROK plug-in voltage monitor measuring voltage range is AC 80-300V(110V, 220V), with a low consumption of less than 1W (about every 1200 hours consume 1 kilowatt-hour).2.Adjustable Potentiometer: Theres an Interior Potentiometer inside the meter for accuracy adjustment. Just use screwdriver to open the outer case and adjust the potentiometer with small size screw driver. Adjust the potentiometer counter-clockwise when its excessive voltage; if the displayed voltage is too low, adjust the potentiometer clockwise.3.Flat Plug: Designed as a flat plug, this volt tester can immediately detect and measure the current voltage by connecting to the switch plug or other kind of wall socket, simple and easy to use, it allows you to check on power health of devices for preventing the low voltage damage to your valuable household appliances.4.LCD Display: Built in Premium LCD digital display with blue backlight, this voltage monitor is convenient for you to view the data on it even in dim night. Moreover, it can be used as a voltage meter as well as a night light.Wide Applications: It is ideally applicable to measuring the AC voltage in family, office space, industrial and mining enterprises, etc. (Please keep the children away from the product & do not use the product in a damp environment.)"