Perfect item will buy another one again
well, it works, and the measurements look reasonable. the soldering was done hastily, with one joint that *had* to be corrected (the solder blob barely touched the PCB), and ugly flux residue all over the place. some of the pins were not properly truncated, so they would be shorted by the battery sooner or later. the distance nuts and bolts are made from plastic, and definitely feel fragile. the MCU is from the STC12 series if someone cares. :D it was packaged in a cardboard box as depicted. the box was wrapped in some thin foam, which was put into a yellow bubble-wrap envelope - the last part is a bad idea, because the box is too thick for that, causing deformation of the envelope, which was probably the reason why an edge was torn so much that the german postal service had to tape it over.