First class product, unbeatable price..
Detailed instructions are missing, however one can find them among product pictures and customer reviews..

Best DC converter on the market.

I've gotten another DROK 2596 buck converter which I really liked. It died when I exceeded the long-term current limit and overheated the chip. So I knew I wanted one with a heatsink and a constant current mode. This has both plus the shell and USB output for the same price - around 9 bucks US. I had a little trouble with some of the cheap screws threading but that's okay.

I haven't put it through the paces yet but if the old one (same board minus the CC pot) is anything to go by, this little guy will be a workhorse on my bench. That's a steal for the same price as a Whopper meal.

Works as expected and more or less as advertised. The voltage and current readings are off a little but really, that's not the point of this thing. I found that it shut off when voltage dropped below 7.5V so keep that in mind for your application. This didn't work well for my intentions because there is a (roughly) half second delay on start-up. That's not the manufacturer's fault, I just had not thought about that possibility. Thinking that has to do with the circuit protection? Anyway, I was just trying to use this to integrate an LED strip into a custom third brake light but the delay makes this product inappropriate for that purpose.

The converter appears well built, is easy to set up, and ran cool (of course, my settings were only 200mA CC around 28V)

This is a very cool product and priced right.. I run it piggy back on a 20 amp switcher and it's really nice.