... productsFeatures:with gauges,monitors,power supplies,circuit boads all in one body,small size,light,fast testing,simple operation,high measurement ... (water content) Operating voltage: DC 15V (10V ~ 20V battery one piece) Using Conditions : The test object environment temperature 0 ~ 40 ... connected) Press the range switch I, then the following one LED should light. Cut the right-left draw point short ...