Barely worn, comes with the charger. The Oura Ring Gen 4 in Silver, Size 12 is an electric cordless activity tracker by Oura Health. It is suitable for indoor and outdoor use and provides measurements for heart rate, calories, and distance. The ring is made of titanium and metal and has a battery life of up to 7 days. It offers features like temperature monitoring, average speed tracking, sleep tracking, and measures SpO2 and accelerometer data. The ring is designed for running and jogging activities and is compatible with both iOS and Android operating systems. Made in Finland, it comes with a 1-year manufacturer warranty.