It has been a while since I have look around at the belt gizmo and what I am seeing is a lit version while awesome I am curious was this a fan made feature of cool or was it in the busterverse before? And are there any theory as to what it is for?
The Belt Gizmo never lit up in the films, that’s a neat little invention courtesy of the fans. 
There are a lot of theories bounding about as to what it was for, but there was never any explanation for it in the movies. The cartoon on occasion suggested it was a radio, or communication device of some sorts… but this was never consistent.