Oura Ring 4 revealed with flat, all-titanium design, 8 days of battery life and new Oura app experience Tom’s GuideThe Oura Ring 4 has slimmer sensors, increased accuracy, and more sizes The VergeOura announces new smart ring with updated design and new sensors for $349 CNBCOura Ring 4 First Take: More Titanium, Better Accuracy and Longer Battery Life CNETThe Oura Ring 3 is discounted to $299 on Amazon for a limited time – and I highly recommend it ZDNet