The Oura Ring 4 is a versatile smart ring designed to monitor various aspects of health and fitness. With advanced sensors, including accelerometer, heart rate, PPG sensor, and temperature, it provides comprehensive tracking of sleep activity, heart rate, blood oxygen saturation, and menstrual cycle data. This device offers features like auto-activity detection, sleep recommendations, and a daily readiness score to optimize well-being. Recharge quickly with its lithium polymer battery in 80 minutes, and enjoy the convenience of wireless charging. The Oura Ring 4 is built to withstand different environments, operating in temperatures as low as -10°C and as high as 54°C. With a water-resistant design that withstands depths of up to 100 m, this smart ring combines durability with functionality, making it an ideal companion for various activities and conditions.