This “bug” works on a frequency of about 89MHz FM, and can be received with every standard FM radio.
This kit is super easy to build, just follow the silkscreen print on the PCB. You will need a CR2032 lithium battery to make it work (not included).
The range and frequency stability is very limited, the signal will not pass more than 2 walls, and the frequency will drift with changing temperature, for example. But it is definitely fun to listen to what’s going on in the basement, garage, or kids room 😉
PCB size is 49 x 26mm. Schematic is included with the product.