Oura has introduced the Oura Ring 5, which is notably smaller and lighter than the Oura Ring 4, making it more comfortable for extended wear. The new model, starting at $399, is designed to be 40% smaller and boasts a battery life of six to nine days, surpassing the five to eight days of its predecessor. Additionally, the Oura Ring 5 features a new scratch-resistant coating and an improved IP68 rating for enhanced durability. However, the Oura Ring 4 remains a strong contender for those needing a broader range of sizes, as it accommodates sizes from four to 15, while the Ring 5 is limited to sizes six through 13. Both models will receive similar software updates, including features like the Health Radar for monitoring health patterns and partnerships with medical AI services. Users seeking a more discreet design and longer battery life may prefer the Ring 5, while those focused on size options and existing software features might opt to stick with the Ring 4.