Rumors of OnePlus releasing a smartwatch in Q1 were finally put to rest when the company took to Twitter to confirm that they would be announcing one alongside the OnePlus 9 series. While it did a good job of keeping details about the wearable under wraps, a new leak tells us almost everything we'd like to know.

According to reliable tipster Ishan Agarwal (via Pricebaba), the Watch will have a 46mm circular dial and be available in both standard and LTE variants. If you were expecting OnePlus to experiment with colors, you might be disappointed to learn that it'll only be available in silver and black.

According to a follow-up tweet by Ishan, the watch doesn't seem to be running on Wear OS. This doesn't necessarily reduce the appeal as it looks like it will be chock-a-block with features. The IP68 rated wearable will support automatic workout detection, a swimming mode, sleep and stress tracking, heart rate monitoring, and an SpO2 sensor — it has a lot in common with the OnePlus Band.

On the smart features front, there's support for calls and notifications, music control, and the ability to control OnePlus TVs. There's 4GB of onboard storage, probably to play music offline via Bluetooth earphones. OnePlus is bringing its Warp Charge tech to the watch, with a 20-minute top-up apparently providing a week's worth of battery.

After the latest batch of leaks, OnePlus made a more expansive announcement on its forum, complete with a teaser image. The text is mostly PR fluff that confirms a few of the leaked specs, but the company did promise a "best-in-class experience at an affordable price point." It also says there will be seamless connectivity with OnePlus phones, peripherals, and even the OnePlus TV. The post confirms that the watch will be fully revealed at the March 23rd event.

There's an interesting reply when the OnePlus CEO was asked whether the watch was running Wear OS or something custom:

We chose to go with a smart wear operating system developed based on RTOS because we believe it provides you a smooth and reliable experience while offering a great battery life, covering some of the biggest concerns we've been hearing from people looking to buy a smartwatch.

RTOS stands for "real-time operating system," a generic term that refers to an OS designed to process data as it comes in. But a lot of cheaper wearables use this kind of software to achieve efficiency: FreeRTOS is an open source option that's popular among low-power fitness trackers and wearables, like the old Pebble. So while OnePlus didn't outright state that it's not using the much-beleaguered Google smartwatch platform, its non-answer certainly seems to indicate that.

CEO says OnePlus Watch will run on RTOS

Story updated to include a forum post from OnePlus, with operating system details.