Preron

Preron is a metallic substance mined from mountains and large rocks. It is found in spider web-like deposits. Preron's main use is the creation of Preron slabs. Preron is first melted down and cast into a slab, the casting is then measured and sawed in two equal pieces. The separated slabs inhibit a phenomenon where they remotely transmit their vibrations between each other. If the slabs ever touch after separation, they will self-destruct in a violent feedback loop. The slabs' ability to transmit the vibrations is based on the distance between the two and the size of the slabs. If two pieces are made in different sizes, they will send the same energy in the vibrations between each other, but the pattern becomes different between the two slabs.

Applications
Preron slabs can be used to remotely transfer kinetic energy. For instance, one slab could be vibrated, causing the other one to also vibrate and power machinery, eg. a digger.

It is also possible to create handheld devices that can be used to communicate with someone if a small slab is attached to a delicate mechanical vibration enhancer to produce sound from the slab's vibration. These small devices would have short range. Colossal slabs are also forged to create long distance communication devices for towns and nations. Simply put: Preron slab communicators are essentially fixed two point radios that have longer range based on their size.

It would theoretically be possible to encode multiple streams of frequencies in a single stream. This is what modern cell networks use to transmit multiple calls at once, dividing their available frequency ranges into blocks and interpreting those as whole spectrums at an acceptable loss of quality. However, it would require very sophisticated computers which are not available.