Oura Ring 4 Ceramic is a modern expression of our revolutionary smart ring technology that blends refined elegance with everyday durability. The high-performance ceramic exterior is designed to keep up with you and all that you do. The Ceramic Collection is available in four unique colors: Midnight, Petal, Tide and Cloud. Each new color is built to accent your style and personality. This colorful new take comes with the same cutting-edge technology of Oura Ring 4. Track over 50 health metrics and get personalized insights into your sleep, activity, readiness, stress, heart health, metabolic health, women's health and more. It is built around a breakthrough sensing technology, Smart Sensing, which adapts to your finger to deliver accurate, continuous data. With 5-8 days of battery life, you'll see a complete picture of your health. It's designed with recessed sensors on the interior, making it comfortable and gentle, even on sensitive skin. Oura Ring 4 Ceramic comes in sizes 4-15 and four stunning finishes to fit your style and your finger, effortlessly. Keep your Oura Ring 4 Ceramic looking like new with the Ceramic Polishing Pad. Once you activate your Oura Ring 4 Ceramic, you~ll receive an in-app message and email with instructions to redeem your free Ceramic Polishing Pad. Due to the hardness of the zirconia ceramic, it can take on the color of softer metals, like a dumbbell or cookware. Over time, you may notice grey marks on your Oura Ring 4 Ceramic. Rest assured, it's not damaged ~ it's evidence of a metal transfer and easy to remove with proper cleaning. Use caution when handling metal objects and consider removing your Oura Ring for some activities. The Oura Ring 4 Ceramic Polishing Pad is your partner in keeping your ring in top condition.