I records electro-magnetic frequencies or something.
Yes, that's (almost) exactly what it does. It allows you to make audible the electromagnetic radiation emitted from devices by converting them into an audio signal. It does not record, though, but has to be hooked up to a recording device.
from the website:
Elektrosluch 3+ is an open-source device for electromagnetic listening. It allows one to discover sonic worlds of electromagnetic fields, surrounding our every step. Just plug your headphones & explore.
Elektrosluch 3+ is the most sensitive Elektrosluch yet. By using state of the art operational amplifier, we have managed to significantly improve signal to noise ratio and extend the frequency response (both on low and high frequencies). This will allow you to capture even more delicate electromagnetic sounds with greater detail and definition. Its cover is now made from more robust & frosty plastics for better protection.
Techno starts with a capital 'T', as in TB-303 and TR-808.