*This item is REFURBISHED. Monitor even more of your health with the Apple Watch Series 6. The Series 6 adds pulse oximetry to measure your blood's oxygen levels (SpO2) in just 15 seconds, as well as showing you your VO2 Max (maximum oxygen consumption) score. These indicators can provide early warnings to possible respiratory conditions. They are joined by an optical heart rate monitor and the ability to record your own ECG (electrocardiogram). The Series 6 can even detect and help you with healthy habits, such as hand-washing detection, which displays a 20-second animated countdown as you scrub.