The device is a DIY LoRa transceiver (868 MHz) in a disposable vape enclosure. It was not designed to be operated by a cat, but the cat does not seem to care about that.
And I also wasn't sure of health hazards of gigahertz radio emissions in relation to cats - my design had the antenna in a VERY close proximity to the cat's body, so that would have been yet another problem to solve...