2 Pack LM2596 DC to DC Voltage Regulator 4-40V to 1.5-35V Buck Converter with LED Display

Good product, doing what should.

Absolutely brilliant. You’ll need to turn anti clockwise to drop power, it takes a lot of turns, like 15-20 before you see anything happen. The led display works great just click the input/output buttons to switch the display, no voltmeter needed.

Works well, good price, terrible instructions! I had to read the instructions over and over again but by a process of elimination figured it out. 1) Connect any DC power supply up to 40v into the left in+ connector. 2) You switch on the device by pressing the left little black button (on the input side IN+). It will then show you the input voltage on the digital display assuming the red light is showing on the left. 3) Then if you press the right button, it will show you the output voltage. If you press the right button again, you will see the input voltage again, and vice versa. 4) Go back to the output voltage, to adjust it. 5) Hold down the right (output OUT-) button until the display starts to flash. Then if you press the right button (while the display is still flashing) the output voltage will increase by one tenth of a volt each time you press the button. Or if you press the left button (while the display is still flashing) the voltage will go down by one tenth of a volt each time you press the button. 6) Then hold down the right button for a few seconds, and the display will stop flashing, and lock the output. 7) Then if you press the right button, it will show you the output voltage, then press it again to show the input voltage on the left. Each time you press it, it show the other voltage. The instructions picture indicates that turning the tiny brass screw will increase or decrease the output voltage. This does not seem to happen, it doesn't do anything, you adjust the output voltage as above.

Edit: seller contacted me regardless and he was very nice to send me another pair of these, he first tried to troubleshoot the problem, the new pair works as intended and of course because my very first ones was completely faulty. As of now i recommend them but always check with a volt meter before using on any device.

Adjusting the input voltage made no difference to the output voltage at all. So you can ignore the buttons and the led display. However like another review I read I turned the small brass screw anti clockwise with I watched with my own voltmeter till I got the output voltage to where I wanted it. Let’s hope it lasts

I basically been looking for a buck regulator to use in my project most of the ones I came across either don't work or don't do what they're described as but this one does I'm using a 12 volt power bank inside my project and I needed five I'm using a 12 volt power bank inside my project and I needed five six and seven volts in different locations so these it did exactly why I needed I may end up buying a couple of more later on highly recommend yes I also like the fact that it has a display on it to show you the exact voltages just in case you don't have a multimeter.

With great acracy I can down scale voltage to my exact requirement being 1.6v say so happy and great value for money

Like everyone else I read the instructions as wind the potentiometer clockwise to reduce the voltage. Not correct, anticlockwise will bring the voltage down at the far end of pot range. The digital display is handy for input or output reading. Good.