It appears to be rather unchanged since the earlier devices. http://www.centraltimeclock.com/security/watchclock.php http://www.centraltimeclock.com/security/w

It appears to be rather unchanged since the earlier devices. http://www.centraltimeclock.com/security/watchclock.php http://www.centraltimeclock.com/security/watchclock.php (the brochure and manuals are interesting) And an old one ( https://youtu.be/xwkIzphNFZY https://youtu.be/xwkIzphNFZY - annoying music) Clock with a rotating piece of paper in it. When the key is turned, it alters (cuts / stamps) the paper. The modern ones are modern made, but the design remains rather unchanged.