Application: DIY mobile power, monitor power supply, power buggies, camera power supply, car power, communications equipment supply,etc. Package includes: 6 x Mini MP1584EN DC to DC buck converter You can adjust the voltage by placing a multi-meter on the output, synchronously, using a screw driver to adjust a potentiometer.
https://www.amazon.com/MP1584EN-DC-DC-Converter-Adjustable-Module/dp/B01MQGMOKI