PROVIDE THE MOST COMFORT: Comfortable ring frees your finger like wearing nothing. Nonslip. No numbness. TRACK YOUR BODY EVERY SECOND: Wear the ring, it will automatically start to track your overnight heart rate and body motion continuously. SMART ALARM: Tell you when Abnormal Heart Rate is detected. FREE REPORTS: App & PC Software provides professional analysis reports. O2Ring works independently or together with app & PC Software. Export detailed reports in CSV/ PNG, easily share for analyzing purposes. CUSTOMIZE YOUR VIBRATION: You can adjust the intensity of vibration separately. You can also set your own threshold on the smartphone. This device is for Sports and Aviation use only and not intended for medical use.. This product is intended for sports or aviation use only. It should not used to diagnose or treat any medical condition. It is not recommended to use it with a defibrillator. Wellue O2ring oxygen monitor is intended to be used for continuously monitoring of oxygen level and pulse rate of adults during sleep overnight and daily activities. Wear the device during sleep, it continuously monitors your SpO2, heart rate and motion. Next morning, open Viheath app and PC software to sync data which will help you understand your sleep oxygen trend. Graphic sleep report is easy to share and print. Note: It should not be used to directly diagnose or treat any medical condition. Start working 1)Wear the sensor on thumb finger, index finger as an option in case of too tight for thumb. Try to move the sensor along the forefinger to find out a best fit. Avoid being loose. Loose wearing causes inaccurate measure. 2)Device will turn on automatically when you wear it. After a few seconds, the device will begin to monitor. App name: ViHealth Notice: if you have installed the App before, please update it to the latest version. PC software PC Software: O2 Insight. Install the software on Windows(win 7 or above) or MacOS(10.13 or above). With the optional PC software, you can view and print sleep report, which can also be exported as PDF or CSV files. Specifications Charge time: 2-3 hours Battery life: 16 hours for typical use oxygen level range: 70% to 99% O2 Accuracy: 80-99%:±2%, 70-79%:±3% Pulse Rate range: 30 to 250 bpm Pulse Rate accuracy: ±2 bpm or ±2% Recorded parameters: O2 level, Pulse Rate, motion Data storage: 4 sessions, up to 10 hours for each