But there’s no arguing over which iconic watch is the most affordable. That title undoubtedly belongs to the Casio F-91W. The ubiquitous and dependable digital watch can often be had for less ...

The Casio F-91W is probably the most popular wristwatch ... There’s a lot of history in this classic watch. That said, there is exactly one problem with this watch: it’s barely water resistant.

[Mattia] decided that a spare key card might be good to have around, and that building it into his Casio F-91W watch would put the key as close at hand as it could be without getting an implant.