Apple have announced the Apple Watch Series 6, the latest addition to the popular wearable line, which includes new internals and upgrades, but also features a new Blood Oxygen tracker.

“Apple Watch Series 6 completely redefines what a watch can do,” said Jeff Williams, Apple’s chief operating officer. “With powerful new features, including a Blood Oxygen sensor and app,1 Apple Watch becomes even more indispensable by providing further insight into overall well-being.”

Blood Oxygen is important as it determines the amount of oxygen in the blood, if there is not enough, you can pass out, something that this clip from the old Top Gear highlights very well.

To compensate for natural variations in the skin and improve accuracy, the Blood Oxygen sensor employs four clusters of green, red, and infrared LEDs, along with the four photodiodes on the back crystal of Apple Watch, to measure light reflected back from blood. The feature is designed in such a way that it can measure blood oxygen between 70 per cent and 100 per cent. On-demand measurements can be taken while the user is still, and periodic background measurements occur when they are inactive, including during sleep. All data will be visible in the Health app, and the user will be able to track trends over time to see how their blood oxygen level changes.

Much like the Watch SE, the Series 6 will be available starting this Friday, September 18 with orders being taken online now. Prices start at $599 for the GPS model and $749 for ones with mobile coverage included. If you want to look at all the options, you can do so here.