It is a Buck Converter/Power Supply Module/Adapter, Input Voltage: DC 4~30V (limit 36V), Output Voltage: DC 1.2~30V (adjustable,default output 5V), Output Current: 0~10A, Application: DIY Power adapter/Charger, industrial equipments, electronic equipment, Communications Equipment, Power Tools, Car Driving Recorder, Car GPS, Car audio, LCD TV, Advertising screen, LED lights, Fan, intercom and monitor system, etc.