The Circular Ring Slim is the "slimmest and lightest wearable in the world" according to its creators and at just 2.2mm and 2 grams, that seems likely. If you are looking for fitness tracking without interruptions, this is a powerful new contender.
I got a chance to see the Circular Ring back in January at CES 2023, and while it looked compelling, I still felt that it would prove too bulky for some users to adopt it over a smartwatch. After all at least some of the promise of a smart ring is that it is less intrusive than a smartwatch, so that means you have to be able to put it on and only think about it once a week when you charge it (officially 6-days of battery life).
