Apple, America’s tech giant has integrated a new technology into its Series 6 Watch that lets people measure their blood oxygen.

This new feature for its Watch could help people made ill by the coronavirus by measuring people’s blood oxygen levels in 15 seconds. Blood oxygen levels are an indicator of the severity of COVID-19, the disease caused by the coronavirus.

“With Apple Watch Series 6, you can measure your blood oxygen right from your wrist,” Jeff Williams, Apple’s chief operating officer, said on Tuesday.

Apple Watch’s blood oxygen reader, often referred to as an oximeter, can measure blood oxygen levels on command. It also does periodic background readings, which are stored in a user’s health app. Williams said this is important so that people can get readings while they’re asleep.

The announcement comes during Apple’s annual fall event, where it typically unveils new iPhones, iPads and other tech gadgets to a crowded auditorium. This year the company hosted a virtual event because of the pandemic.

Along with helping COVID-19 patients determine how sick they may be, oximeters are also useful for people with asthma, chronic obstructive pulmonary disease, pneumonia and other respiratory illnesses.

The Apple Watch has come a long way from its original launch in 2015, when it was touted as a luxury item that even included in its lineup a $10,000 gold variant called the Apple Watch Edition. Over the last few years, Apple has leaned into the Watch being a health device people can use to track their daily activity. Along with step-tracking, Apple’s health-related features already include an ECG heart monitor, sync technology for gym equipment and a meditation app.

Blood oxygen levels are generally measured using a pulse oximeter on the tip of the finger, and to do this on the wrist Apple had to add new hardware to the Watch — making the feature a Series 6 exclusive. Apple said it’s working with several health care providers and universities to study how blood oxygen levels measured by the Watch can be used in future health applications.

“Apple Watch revolutionized what a watch can do,” Apple CEO Tim Cook said during Tuesday’s event. “We feel a deep responsibility to keep innovating.”