If you're interested in purchasing a smart ring, you should consider the following factors:

• Purpose and functionality: Traditionally, smart rings like the Oura Ring are a substitute for a smartwatch or other health-tracking device. For this list, we considered rings that monitor factors like blood oxygen testing, sleep and heart rate tracking, and activity metrics, but also considered rings with smart nuances, such as NFC readings and making contactless payments.
  

• Durability:To go from jewelry accessories to smart staples, there are certain durability aspects these rings should include to maximize benefits. We considered if the rings were waterproof, water-resistant, or coated with any extra protection.

• Device compatibility: Unlike a smartwatch, smart rings don't have an interactive display. Therefore, all the data is housed via third-party software. We made sure these choices were compatible with iOS and Android.

• Design: One of the benefits of a smart ring is that, ideally, it's sleek, subtle, and comfortable to wear -- even as your finger may swell in the summer heat.