oooh just presented my uni design thingie teacher asked as extra question at the end "who would like to have this product" and loots of people raised their hands :D
it's a thing to help find your bicycle in crowded (station) parking spots, so a very Dutch problem to have :P
veery tempted to open kicad and start producing these but that probably bypasses the actual design cycle for the rest of the group a bit too much :')