Funnily enough, back in 2013, I came across a geocache in Kassel that had an LED platform display mounted to a lamp post on a sidewalk. When you came close, it showed you the coordinates for the next stage. I have now learned that this was actually right next to SaF's (the manufacturer) premises - hence why there was just a random display mounted there - and the geocache owners got them to collaborate. And now, I finally have a display made by SaF myself. Too bad they're bankrupt now.