One year after the introduction of the WSD-F20, Casio unveils the Pro Trek WSD-F20SC "adventure smartwatch" at the ongoing Baselworld 2018 trade show that focuses on wearable technology. Compared to its predecessor, the WSD-F20SC also comes with a sapphire crystal display that can easily handle scratches and bumps, as well as a durable Field Composite band.
https://www.notebookcheck.net/Casio-unveils-the-Pro-Trek-Smart-WSD-F20SC-limited-edition-watch.291738.0.html