Oura Ring 4 review: still on top — for now The VergeWhy the Oura Smart Ring Has a Cult Following The Wall Street JournalThe Oura Ring 4 Is Lighter, Prettier, and More Wearable Than Ever WIREDOura Ring 4 Review: My Favorite Wellness Tracker Comes With a Pricey Caveat CNETThe Oura Ring 4 is sleek and easy to wear but scratches easily. Here’s what it’s like CNBC