Apple Watch Series 10 Prototype With Mysterious Sensor Surfaces Online

Photos of what appears to be an early prototype of the Apple Watch Series 10 have surfaced online, offering a rare glimpse into Apple’s internal testing process—and a curious new sensor design. Shared by leaker @StellaFudge on X, the prototype features a 46mm aluminum case and a mystery health sensor that hasn’t been seen on any current Apple Watch model.

A New Sensor Layout Raises Questions

The underside of the watch reveals a redesigned sensor arrangement. Instead of the usual large central sensor, this prototype has smaller sensors arranged in a circular pattern, along with a light ring around the edge. The model is marked as a GPS-only Apple Watch, and internal labels and a serial number suggest it’s a test unit, likely never intended for public release.

The prototype is running watchOS 11.1 (build 22R5575X)—a version that appears to fall between beta 5 and the release candidate. This internal software build is locked down, only allowing access to stock Apple apps from internal servers, meaning third-party app testing or hands-on use of the new sensors is currently off-limits.

Could This Be a Step Toward Blood Sugar Monitoring?

While the purpose of the new sensor isn’t officially known, @StellaFudge speculates that it could be related to blood glucose testing—a feature Apple has been quietly working on for years.

This theory lines up with a recent report from Mark Gurman, who confirmed that Apple is actively developing a non-invasive blood sugar monitoring system for future Apple Watch models. According to Gurman, the company has hit some major milestones but is still years away from a commercial-ready version.

What Else We Know

• The prototype carries a model number: A294-59296LW/A

• It’s labeled with internal markings like ABX-G08ap-h

• It was designed in California and assembled in China

Though this device may never see a public release in its current form, it gives us a small peek into Apple’s ongoing work to push health technology forward.

As always with leaks, it’s important to take these developments with a grain of caution—but there’s no doubt that Apple is continuing to test the limits of what the Apple Watch can do. If this prototype is anything to go by, the future of health tracking on the wrist could be even more ambitious than we thought.