DC-DC Buck Converter Step Down Module - Walmart.com
UCTRONICS DC 6V 9V 12V 24V to DC 5V 5A Buck Converter Module, 9-36V Step Down to USB 5V Transformer Dual Output Voltage Regulator Board [2 Pack]
DC Buck Converter 6-55V to 0-50V 8A 400W 6V 12V 24V 36V 48V Constant Voltage and Constant Current Buck Module, DC Regulated Power Supply, Stepdown Adjustable Voltage Regulator
AC/DC to DC Buck Step Down Converter 3V 5V 12V 15V 24V Rectifier Filter Module | eBay