Note that these sales are for the software only.
The pictures are examples and they tell you which parts you need to build the devices. The software is sold compiled and any buyer needs to run some scripts in advance to provide the seller with internal codes to enable the software to be compiled to match your hardware.
Fair play to the seller, but it’s a small market. A reasonably technical person could build and code their own devices, and there is open source code and demos there for free - the seller is marketing their game modes and device design
We build our own, with our tech guy building professional standard ones and me experimenting with less professional ones …… (and ours aren’t for sale, as they are designed around our game modes for our events)