DROK Waterproof DC Buck Converter Voltage Regulator 8-22V to 1-15V 5V 12V 3A Adjustable Output Power Supply Transformer Uses synchronous rectification technology, has high conversion efficiency and Stable performance; the input should be at least 3V higher than output With potentiometer on the bottom, which allows you adjust the accuracy with the mini screw, but ensures you won't easily change its setting when mounted Fully sealed, outer enclosure acts as a heat sink, specially Made to be waterproof, anti-shock, anti-humidity and dust-proof, more durable With reversed-connection protection, over-current protection, over-heating protection and over-voltage protection, hence is safe to use Perfect for electronic hobby project, wide application, you can use it on radio, car audio, LED display, motor, Cell phone, etc