Engadget review: Una's $249 modular GPS watch is repairable but less rugged

Una was founded by Lewis Allison, the former chief technology officer of Scottish golf watch company Shot Scope. The company's slogan is "one watch for life," and Engadget said Una is not charging a premium for the hardware; the watch costs $249. Engadget noted that repairable smart watches are rare, with Google's Pixel Watch 4 setting a bar but remaining an exception. The EU added a carve-out to its e-waste rules for small devices, underscoring the difficulty of making such gear sustainable.

The watch looks like a generic 46mm GPS running watch, with a chunky case similar to a Garmin Fenix, four buttons and a silicone strap. Engadget noted differences such as an exposed USB-C charging port on the right side, where a crown would normally sit, and real Torx T3 screws on the front and back. The display is a 1.2-inch Memory In Pixel LCD with 240 x 240 resolution, covered by hardened mineral glass.

With a Torx T3 tool, users can break the watch into six parts that can be swapped fairly easily, according to the review. After removing the display module, there are two separate sensor modules, one for GPS and one for Bluetooth. Below them is the Core section, which contains a Cortex-M33 microcontroller, 2.5MB of RAM and 4GB of eMMC storage. It also includes a vibration motor, piezo speaker, altimeter and temperature sensor. The system runs FreeRTOS, which Engadget described as a kind of open-source operating system for tiny embedded systems.

Una has posted all of its software, housing and circuit board designs on GitHub and runs a developer forum for collaboration. Engadget said that given the shortage of open-source watches, the open-source community will likely embrace the device. On the back, the rear cover unscrews to reveal the PPG sensor module. The remaining 280mAh battery is held in place with one additional T3 screw. The battery is expected to last between seven and 10 days on a charge, with GPS performance pledged at 20 hours. Engadget got seven days from a full charge, including several short walks and workouts with GPS.

The trade-off is durability. Engadget said the hardware is IPX5-rated, meaning it can withstand rain, sweat and light splashes of water. The review pressed Una about the exposed USB-C port and the lack of a gasket. The company said the USB-C port itself is IP68-rated, which should ease some concerns. But Engadget said it suspected the watch is not sturdy enough for events like Tough Mudder, and it noted that the rubber gaskets inside the top and bottom covers appear very thin.

In use, Engadget said a phone-connected GPS watch is not a smartwatch, so expectations should be adjusted. There is almost no customization; the only watchface change is between 12- and 24-hour time. Three separate menus are triggered by different shoulder buttons: the main menu, detailed activity data and the list of trackable workouts. Trackable workouts are limited to walks, runs, hikes, bike rides, treadmill running and a generic workout. Users are already filling gaps with their own tracking apps, which can be shared with others through the mobile app. Engadget said it would not expect a watch like this to have automatic tracking, especially for its target market of hardcore fitness users.