Long Time Tracking: Continuously tracking and recording blood oxygen saturation level, heart rate and motion every minute, continuous using up to 12 hours after fully charged Customizable Notification & Vibration: WearO2 oxygen monitor notifies you with a vibration when your blood oxygen drops below your preset level (adjustable from 80% to 95%). This alert feature can be enabled or disabled at any time Free APP for Android & iOS: The Vihealth APP shows real-time data during measurement. Users are able to store and compare long-term data in app without addtional cost, and share the report with others in PDF/CSV form. Integrate with Apple Health Patent Ring Sensor: Gentle on your fingers, the patented WearO2 silicone ring sensor is easy to put on and designed to avoid discomfort, soreness, or numbness. It's crafted to be worn comfortably long time Large-Capacity Data Storage: Built-in with 4 sets memory, each set can up to 10 hours, and data will automatically synchronized to the APP via Bluetooth. (APP supports unlimited storage) Note: It's not a medical device. This device is for Sports and Aviation use only and not intended for medical use. Please use just before or after exercise, and keep your body calm to prevent unreadable or inaccurate readings It's not a medical device. This device is for Sports and Aviation use only and not intended for medical use.