The Oura Ring Gen 4 in size 10 is a sleek black activity tracker designed for both men and women. With a high-resolution display of 240 x 240, this ring provides accurate measurements for heart rate, calories, and distance. It operates on batteries with a battery life of up to 7 days and offers a variety of features such as a sleep tracker, accelerometer, and GPS sensor. Perfect for indoor and outdoor activities, this Oura Ring Gen 4 is a stylish and functional tool for tracking your fitness goals.