Minimum input:DC4.5(Below this voltage,it will show measurement inaccurate,or don"t show). Maximum Input:DC30V(please do not exceed 30V,otherwise,the meter would be damaged). Power supply:No need power supply. Current consumption: Less than 20 mA, general 5-15 mA. Working temperature: -10¡æ ~ 65 ¡æ. Allowable error: 1% (+ /-1). Display colors:blue. Package include: 1 x DC 4.5-30V LED digital display Voltmeter. Please note: 1> niceeshop(TM) is a registered trademark and the only authorized seller of niceeshop branded products. 2> niceeshop provide you various kinds of great products at the lowest possible prices, welcome to our store and get what you want !!! 3> niceeshop highly appriciate all customers" opinions to improve the selling ,also if anything you unsatisfied, pls contact our customer service department for probable best solution.