My Dad's Rolex Oyster diving watch.
He wasn't amused when, as a curious boy, I took the guts out of it, just to, ya now...see how it worked?
I'm sure some of you are wondering why I might consider a watch to be tech-based?
Well, considering that almost three quarters of the population was still using those pesky wrist-sundials, that Rolex was hi-tech, believe me.