RioRand DC/DC BUCK Stepdown Converter Regulator 4.5-40V 12V To 5V/2A USB Charger Voltmeter Display Powered by RioRand Advanced Technology voltmeter range and Input voltage: DC 4.5~40V, (please input dc 6.5 ~ 40V voltage, then can get a 5.0V stabilize output) Output voltage/current: 5V/2A, high-efficiency, low ripple one button "Output Enable" switch USB output, one button "Low Power" turn off the voltmeter display oltmeter display can be calibrated, Module dimensions: 58mm * 21mm * 10mm (L*W*H). with USB power indicator, with reverse polarity protection, with over current, over temperature protection