According to Apple, the Series 4 represents "a fundamental redesign and re-engineering of Apple Watch." As a result, watch out for a lot of very cool changes, from the curved corners to the all-new and larger display.
The Series 4 provides lots to talk about but it's the display that is capturing the most attention. The narrow borders deliver a viewing area that’s over 30 per cent larger! The curved corners match the radius of the case, allowing for images and the touch surface to almost extend to the very edge of the screen.
Because of the bigger display, the design of the interface has been remodelled with the new Infograph watch face now capable of handling eight complications, allowing you to do more and see more at a glance.
The optical heart sensor has always been a feature of the Apple Watch, but in the Series 4 it can now detect if your heart rate falls below a specified threshold for a period of 10 minutes, and activates a low-heart-rate notification as a result.
The Series 4 is a complete SiP a System in Package. This means the entire system is fabricated onto a single component with some incredible capabilities crammed into that small device.
The Apple Watch Series 4 boasts improvements in virtually every sense, and that includes a speaker that's 50 % louder for enhanced audio quality for things like Siri and the Walkie-Talkie function. Meanwhile, the microphone is now on the other side of the watch to minimise echo when making phone calls.
A newer model Apple Watch Series 5 40mm Aluminium Case with Sport Band was released in September 2019.