SMAKN&reg; Digital Readout Dc 4.5-24v to 1-20v 2a 20w Buck Voltage Converter Power Supply Dc/dc Constant Voltage and Current Buck Converter Voltmeter(BLUE) Voltmeter: Input 4.5-24.0V output 0.9-20.0V Ammeter: 0.00-2.00A(Only display output current) Dimensions: 51.5 *33 *20mm(length*width*height) Display color: Blue/Red/Green Input voltage: 4.5-24V(Maximum limit voltage is 24 v,please leave some leeway to use ,otherwise be damaged)