1. Backlight control: Briefly press the key to turn the backlight on or off. 2. Reset : Long press the key for more than 3 seconds can reset the . 3. Current indication: The current has a direction indication, if there is "-", it means the current is in the reverse direction, otherwise it is the forward direction. 4. indication: has direction indication, if there is "-", it means is reverse direction, otherwise it is forward direction.The direction is judged according to the current direction, if the current is positive, the increase, the maximum is 999kwh, the overflow be maintained unless you reset it; if the current is reverse, the decrease, the maximum is -999kwh, the overflow be maintained unless you reset it 5. Working mode: Direct power supply: direct supply by test voltage, test range is: 8-300V; power supply: working voltage range is: DC5-12V, test range is: 0-300V, Weight: 0.39903669422 Pounds, Manufacturer: Ehwisbe