If you didn’t have it already, blood oxygen sensing is again available to U.S. users with the rollout of iOS 18.6.1 and watchOS 11.6.1.

On Thursday, Apple announced that it would be bringing the much-missed Blood Oxygen feature to Apple Watch Series 9, Apple Watch Series 10, and Apple Watch Ultra 2 via a pair of updates to both iPhone and Apple Watch. Those updates are now available to download for affected users’ devices.

Apple hasn’t disclosed what was done to resolve its patent dispute, and probably won’t say anything else about it. It did say that the move was “enabled by a recent U.S. Customs ruling.”

Once a user updates both devices, sensor data from the Blood Oxygen app on Apple Watch will be measured and calculated on the paired iPhone. Results are viewable within the Respiratory section of the Apple Health app.

The years-long battle began all the way back in 2020 when Masimo alleged Apple stole trade secrets and infringed ten patents used in the Apple Watch’s health tracking features. Masimo also accused Apple of poaching staff and using confidential technology without proper credit.

Apple disabled the feature via software to keep selling the Apple Watch in the United States during the appeal process. The feature had been absent from Apple’s flagship wearable for more than 18 months.

The release of iOS 18.6.1 has build number 22G90. The update’s release notes are brief.

This update provides a new Blood Oxygen experience for users in the United States with Apple Watch Series 9 and Series 10, and Apple Watch Ultra 2. Measurements are calculated on iPhone and viewed in the Health app.How to update to watchOS 11.6.1Ensure the Apple Watch is charged to at least 50% and connected to Wi-Fi
On your Apple Watch, open the Settings app
Tap General
Tap Software Update
Tap Install if a software update is available
Follow the on-screen instructionsHow to update to watchOS 11.6.1 via iPhoneEnsure your watch is charged to 50% and connected to Wi-Fi
On your iPhone, open the Apple Watch app
Tap General
Tap Software Update
Tap the update if it is available
Follow the on-screen instructionsHow to update to iOS 18.6.1On your iPhone, open the Settings app
Tap General
Tap Software Update
Tap the update to install
When prompted, follow the on-screen instructions

This update does not apply to Apple Watch devices sold outside of the U.S. or those purchased and activated before the initial ban.