Alinan 12pcs Step-Down Power Supply Module Mini DC-DC 12-24V to 5V 3A Voltage Buck Converter Adjustable 1.8V 2.5V 3.3V 5V 9V 12V

This board's voltage regulator ic is marked dkgab which is NOT a 24v regulator, it's max voltage is 18v, so this not as advertised and is NOT going to work for my application! Give it more than 18v and it will fry quickly!

I'm using this quite successfully to switch 12V down to 5V using the static 5V setting, and my multimeter reads it at 4.999V -- stellar accuracy. It's also CRAZY small -- it fits underneath and inside the pins of an Arduino Nano, as long as the nano is mounted on higher headers. The problem is that I spent a little bit more on this model versus others on false pretenses. Most of the other cards have a trace that you need to cut if you don't want to use the potentiometer, but this one leads you to believe you have to put solder on the "Adj" pad to turn the pot ON. I liked that because I hate slicing traces and knew I wanted a static output. It turns out, the pot is on by default, and I couldn't figure out a trace to cut to take it out of the circuit. Just soldering the 5V pad gave me 3V and change. Finally I took the sharp edge of a utility blade and pried the pot clean off the top of the board, and boom, now I'm getting 5V. Still 4 stars because the accuracy (at least with 12V in) is good, and prying the pot off isn't too hard. I'm just miffed I could have gone with a cheaper component.

Works as advertised at 14v (charging voltage for a 12v system) but smokes when connected to 19v. We require a stepdown from 19v (Milwaukee M18 battery pack) to 9v and it will not work. Have burned up 5 units thinking I was doing something wrong.

Amazon sent in a padded envelope, but Alinan puts them in a sandwich baggie and they knock the parts of each other in the tossing about in shipping. I would guess the solder joints are pretty bad too at this rate...