DROKxae; Dual Display Digital DC Voltmeter Ammeter Amp Meter 0-999mA Voltage Meter 0-33V DC 3.5-30V Power Supply Volt Current Meter Tester RB Display &iexcl;&shy; DC ammeter and Voltmeter with accuracy  1 percent 2digits, three 0 28-inch dual LED digital tube Voltmeter range is DC 0-33 0V, ammeter range is DC 0-999ma, power supply is DC3 5-30v - Easy to use, power is from Measured circuit when testing current, needn't separate power supply Refresh rate is 500 times/MS which make it work efficiently, operating temperature is -10~65 With a tiny Size 48 x 29 x 26 mm and its installing Size is 45 x 26 mm