Why the Oura Ring 4 is still the best smart ring on the market - and I've tested dozens of them

ZDNET's key takeaways The Oura Ring 4, the newest generation of the popular smart ring is now available to buy and starts at $350. During the past few years, Oura has been busy developing a smart ring that's smarter and stronger than the rest: the recently unveiled Oura Ring 4. The Oura Ring 4 (left) has receded sensors that make it more comfortable to wear compared to Oura Ring 3 (right). Also: Oura Ring 3 vs Oura Ring 4: Should you buy the discounted smart ring or the brand's newest? Most of the hardware upgrades prioritize comfort, so if you already have an Oura Ring 3, I'd only buy the Oura Ring 4 if you can't stand the uncomfortable protruding dome sensors of the earlier generation.