The Brand New and Sealed Oura Ring 4 in size 8, in silver, is an activity tracker perfect for both indoor and outdoor activities. Made from titanium, providing accurate measurements in both decimal and imperial systems. With a battery life of up to 7 days, it also offers features such as Bluetooth connectivity, exercise log, smartphone compatibility, sleep tracker, and average heart rate calculation. The Oura Ring is designed for unisex adults and has a 2-year manufacturer warranty, making it a reliable and stylish accessory for tracking your fitness goals.