Does exactly what I need
For 12A adjustable DC-DC step-down module
Took almost three weeks to arrive from China. They hauled it to New York on its way to California... The bottom side had strange white powdery residue (partially dissolved heat transfer paste?) as well as solder flux from final assembly, which cleaned off nicely but shouldn't have been there at all. Once it looked good I wired it up and it worked perfectly. Really no documentation needed, everything is obvious. Easy to dial up exactly the voltage I need, to two decimal places.
