Knight Rider sparked my love of digital watches. Particularly geeky/gadget watches. I don’t think the exact model of the watch that was used in the show was ever discovered because the prop department had a sticker over the face of the watch. One of the most popular watches that matches the one in the show is the “Advance” radio watch. There are several other watches that have similar designs with different branding, functionality and display layouts. I got this Piratron radio watch yesterday which has the correct display layout (seconds top right) as was used in the tv show.
Some other variants I have including the replica prop that was produced fairly recently. The one on the right with the sticker over it is a “Bradley radio watch”.
I put a fresh battery in the Piratron last night. It was working great. I woke this morning to see the display has started fading on and off every time the seconds tick by. Although you can still read the display normally (every other second that is) I’m pronouncing it dead. Lasted all of 12 hours lol.
The 3rd one from the left, with “engage” written on it, is a reproduction replica. I think they were produced about 5 years ago by a knight rider fan in America. I have had 6 brand new ones and everyone of them resets the time if you wear it. There must have been some problem with the manufacturer. I packed the module tightly on my current one and it hasn’t reset since I modded it.