I've noticed "magic" BLACK box on this video (at 2:25) with AC socket and jumpers:
https://youtu.be/4VedR-NUORMI'd like to buy such thing. I know, that it's quire easy to be build on my own, but I like "safe" jumpers, which are "essential" for this design...
What is the "merchant" name of this thing or, maybe, where it can be bought?
Regards.
Edit. O'k, I've found jumpers, but still...