Apple is halting sales of its Apple Watch Series 9 and Ultra 2 devices. Here’s why.

Apple said it will halt sales of some of its Apple Watch products later this month because of a patent dispute over the devices’ blood oxygen monitor. 

The technology giant said it is “preemptively taking steps to comply” should a ruling hold from the U.S. International Trade Commission (ITC) over the patent dispute. 

“This includes pausing sales of Apple Watch Series 9 and Apple Watch Ultra 2 from Apple.com starting December 21, and from Apple retail locations after December 24,” Apple said in an email to CBS MoneyWatch. 

The legal dispute stems from the blood oxygen feature in the devices, which allows Apple Watch users to measure the level of oxygen in their blood. Low blood oxygen levels can lead to serious health problems, according to Cleveland Clinic. 

Apple’s decision comes after the ITC ruled that the tech giant had illegally incorporated blood oxygen technology from Masimo, a medical tech company, and ordered Apple to stop importing the devices. A presidential review panel is now reviewing the ITC’s order, with that review period slated to end on December 25. That deadline prompted Apple to pull the devices starting later this week. 

“Apple strongly disagrees with the order and is pursuing a range of legal and technical options to ensure that Apple Watch is available to customers,” Apple said in its email.