High quality brand new About blood oxygen: (Normal range: 95%-99%, usually 99), when there is strenuous exercise, such as climbing mountains, after running, or cardiopulmonary dysfunction the blood oxygen concentration may be lower than 99.How to Connect to the App: 1.Scan the above QR code or search for "JRing" on your phone to download it for free. 2.Select your settings based on the actual situation. 3. Open app and set your data. 4. Connect the ring to your phone via Bluetooth.Upgraded Smart Ring: With led screen and touch butto you can effortlessly monitor essential data such as time, step count, heart rate, blood oxygen, sleep, and battery.Monitor from App: Easily connect your smart ring to phone via bluetooth for seamless data tracking and app control. Compatible with Android(5.0+) & iOS(10.0).Multiple Fitness Tracker: Monitor step count, heart rate, blood oxygen, sleep quality ect. It also tracks multiple sports activities such as walking, running, cycling, hiking, and golf, helping you stay on top of your fitness goals.IP68 Waterproof: The vacuum plating technology is used to ensure uniform and dense coating improve the wear resistance and corrosion resistance of the product; sealing technology it withstands water immersion, making it ideal for daily activities like handwashing, workouts, and even diving or snorkeling.Elegant Design: Made of carefully polished from lightweight yet durable stainless steel and resinous, the slim, slick, ring-shaped design is comfortable to wear all day and night.