The Series 4 Apple Watch proved a serious improvement in terms of performance, and added features like the onboard ECG.
Apple's next Apple Watch revision could include new materials for the case, including titanium and ceramic. Rumors have suggested that there will be a new ceramic casing design for the watches, though it's possible that these could be for previous models and not necessarily the series 5 devices. As it turns out, the Cupertino company is also developing the next generation App Watch for launch next month.
The note, which was shared with Chinese media, claims Japan Display will gradually become a prominent supplier of OLED displays for the Apple Watch in Apple's supply chain. Apple will likely also offer these alongside their stainless steel and aluminum models, should they actually be released this fall, and would probably charge a premium for these material options, too. Typically, Apple Watch is launched alongside new iPhones and thus it is safe to presume that both will be launched at Apple's September event. Apple has slowly been moving the Apple Watch in this direction with the introduction of a watchOS App Store and the ability to install updates over-the-air.
The report also reveals that the Apple Watch Series 5 will feature sleep tracking, a larger battery, and more health features.
Despite this new information, there's still little information known about what new innovations or improvements that Apple will be making with Series 5.