You might remember the Elektrosluch 2 from back in 2014.
The following are details on the Elektrosluch Mini City via lom.audio

Elektrosluch Mini City kit contains all the necessary parts, including the plastic top cover and battery. Detailed assembly instructions will be available online once the device is shipping.
Elektrosluch Mini City circuit is identical to Elektrosluch 3+.
Elektrosluch Mini kit is easy to assemble, however some soldering experience is required. We strongly advice you to make sure you're capable of assembling it on your own before you start. If you're not sure what you're doing, find someone around who can help. We won't be able to solve your issues over the internet.
You will require soldering iron, solder, phillips screwdriver and side cutters for cutting of the leads."