Used once!! Original box and charger included. Oura Ring Gen 4 in size 10 is a sleek black activity tracker made of titanium, designed for indoor and outdoor use. It offers a display resolution of 240 x 240 and features an accelerometer sensor for measuring activities. With a battery life of up to 7 days, this Oura Ring Gen 4 provides calories and average heart rate measurements, making it perfect for unisex adults engaging in gym and training activities. Developed by Oura Health in Finland, this ring is compatible with Android operating systems and comes with a 1-year manufacturer warranty.