Display mode: Dual display Current error: 1% Supply voltage range: 5V-100V Voltage measurement input range: 0-300V Voltage resolution: 0.1V Voltage error: 1% name:Hall current voltmeter Measurement Range: + -100A /+ -400A Accuracy: + - 1% Resolution: 0.3A Working current: 7-15mA Sensor hole diameter: 20mm Operating temperature: -4F - 140F (-20C - 60C) Type:Hall Ammeter Voltmeter Style:LED Digital Isolated meter Output Type:DC 5-120V Model Number:dc Voltage Current METER Default wire 0.15M . Use Hall Ammeter of you can measure positive current and negative current. You can measure the current of +VCC/-VCC/GND .Use Hall Ammeter measure any DC current unlimited,for that the Hall Ammeter of measure is isolated. This design allows system designers to monitor any current path without breaking or changing original system layout at all. Instructions: (1)Access Power Supply range 5V to 120V (2)Use electric wire by pass it through the hole of hall current sensor to measure passing current. Colour:Black & Gray Material:plastic style:400A Package Contents: 1 set * Hall current voltmeter Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.