The Oura Ring and the Oura Membership ($5.99/mo plus tax) work hand-in-hand to help you feel your best. Monitor your sleep, activity levels, temperature, stress, heart rate, and more with the most trusted Smart Ring. Whether you’re focusing on your fitness or want to improve your sleep, Oura helps you take control of your health — in style. This ring is 6 months old and in good condition with an excellent battery life (4-5 days between charges!).