Features: 2 in 1 design, voltmeter and ammeter, make you get the data at the same time. LED display design gives you quick reading, can make you distinguish voltage and current easily. This product is made of high quality materials with dustproof processing, reliable and durable for long time use. Measuring range is DC 0-100V, with reverse polarity protection and common ground design, don't need to worry the damage caused by reverse polarity. Easy to install and use, suitable for various uses. Specification: Material: Plastic Working voltage of Meter itself: DC 4-30V Note: The maximum input voltage can not exceed 30V. Otherwise the meter will be burned. Working current of Meter itself: ≤20mA Voltage Measuring range: DC 0-100V Current Measuring range: DC 0-50A, DC0-10A Low operating voltage: + 4.5v High working voltage: +30V Voltage resolution (V): 0.1V Current resolution (A): 0.01A Measure accuracy: 1% (±1 digit) Display: 0.28" digital tube, Two color Blue and Red Refresh rate: about 300mS/ times Working temperature: - 10 ℃ ~ + 65 ℃ Working humidity: 10-80% (no condensation) Size: approx. 48 x 29 x 26mm Operation Temperature: -10℃~+65℃ Size: approx. 48*29*21mm / 1.89*1.14*0.83in Weight: approx. 26g Options(Color of Digit & Amp): Red & Red-10A, Red & Blue-10A, Red & Red-50A, Red & Blue-50A Package list: 1 * Digital Voltmeter Ammeter 2 * Wire .