Worry not; that isn't any sign of danger. The red glowing light indicates that your smart ring is working perfectly fine and measuring your blood oxygen level (SpO₂).

I wanted to see which was best, and the Oura Ring Gen 3 was the clear winner. Well, it’s been about two weeks since my experiment ended, and there’s now a new winner: the Oura Ring 4.

The Oura ring can give you a ton of data on your sleep, health, and fitness, but you need to pay for a $5.99/month subscription to see all of it.

The Oura Ring 4 fitness tracker is a good alternative to the Apple Watch. We break down everything you need to know about features, durability and more.

Make sure you purchase a sizer with the correct metric system, as other countries measure ring sizes in different ways,” she adds. How to measure your ring size at home with a printable chart ...