Working voltage of Meter: DC 4 - 30V Working current of Meter: less than 20mA Voltage Measuring range: DC 0 - 100V Current Measuring range: DC 0 - 10A Voltage resolution (V): 0.1V Current resolution (A): 0.01A Measure accuracy: 1% ( 1 digit) Display: 0.28inch digital tube, Two color blue and red Refresh rate: about 300mS / Dimensions: 48mmx29mmx21mm Operation Temp: -10-+65 Note: The maximum input voltage can not 30V. Otherwise the meter will be burned out. colour:black Material:ABS + electronic components Package Included: 2 x 0.56inch Digital Voltmeter Ammeter DC 100V 10A Blue + Red Dual LED Display 2 x two wires Only the above package content, other products are not included. Note: Light 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.