The meter is a handheld 31/2 digital multimeter for measuring DC and AC voltage, DC current, Resistance, Diode, Transistor, and Continuity Test with battery operated. The Backlight of the display is optional. Display 3 1/2 digit, 7 segments, 15mm high LCD. Backlight (option) When this button is pushed, the Backlight of the display is on. After about 5 seconds, the Backlight is self-off. the backlight is on again, just push this button once. Rotary switch This switch is used to select functions and desired ranges as well as to turn on/off the meter. Hold button When this button is pushed, the display will keep the last reading, and “ ” symbol will appear on the LCD until pushing it again.“10A” jack Plug-in connector for red test lead for 10A measurement. “COM” jack Plug-in connector for black (negative) test lead. “VΩmA” jack Plug-in connector for red (positive) test lead for voltage, resistance, and current (except 10A) measurements. Features/Specs: Overrange Indication: Only figure “1” on the display Polarity indication:“-” displayed for negative polarity Operating Environment :0 to 40℃-4- Storage temperature:-10°C to 50°C. Low battery indication: “Battery ”appears on the display Size :138mm x 69mm x 31mm Weight: Approx.170g.