Holdding Mini 0.36 " LED Digital Volt Voltage Panel Meter Voltmeter 0-100V (Blue) with Three-wires, Reverse Polarity Protection Function and Large Range for Electronic DIY Measuring range: DC 0-99.9V three-wire access Operating voltage: DC 4.5~28V Display: Three 0.36 "LED digital tube; Refresh rate: about 500mS / time Measurement accuracy: 1 %( +/- 1 digit)