The Oura Ring Gen 4 Ceramic Cloud/White Size 9 is a unisex activity tracker that measures heart rate and provides sleep tracking features. With a display resolution of 240 x 240, this ring operates on batteries and has a battery life of up to 7 days. It is designed for both indoor and outdoor use, with a focus on running and jogging activities. The ring is It is compatiblewith Android operating systems and is equipped with an accelerometer sensor for accurate tracking.