Product Specifications BRAND NAME：Wellue COLOUR：Blue MODEL：SleepU WEIGHT：1.09 oz / 31g DEVICE DIMENSIONS：1.6'' x 0.9'' x 0.5'' RING PERIMETER：2.0'' - 3.0'' / 50-76mm WIRELESS：Bluetooth 4.0 BLE BATTERY LIFE：Rechargeable lithium-polymer, 3.7 Vdc, 16 hours for typical use DEGREE OF DUST &WATER RESISTANCE：IP24 RECORDED PARAMETERS：Oxygen levels, pulse rate, motion COMPATIBLE COMPUTER SYSTEM：Windows 7/8/10; macOS 10.15.3 or above COMPATIBLE WITH：iOS 9.0 or above, iPhone 4s/iPad 3 or above; Android 5.0 or above, with Bluetooth 4.0 BLE OXYGEN LEVEL RANGE：70%-99% PULSE RATE RANGE：30 to 250 bpm MEASURE INTERVAL：1S DISPLAY INTERVAL IN APP：4S BUILT-IN MEMORY：4 sessions, up to 10 hours for each session Product Description ☀️【Wearable Oxygen Saturation Monitor】 Patented soft silicone ring sensor totally releases your finger while ensuring accurate measurements. Never slip from your finger, continuously monitor your blood oxygen saturation, heart rate and body movement during sleep all night. ☀️【Smart Vibration to Notify You】SleepU will vibrate gently to remind you to adjust posture when it detects your blood oxygen level falls below the threshold preset, effectively help you sleep in a healthy blood oxygen status, you can adjust the threshold via APP. ☀️【Convenient Report】 SleepU can record your blood oxygen saturation and heart rate continuously, and generate trend reports on APP or PC software, you can save the report as PDF to print or share with others. ☀️【Intelligent Data Management】 Built-in memory allows it to work independently without a phone. The data will be synced to your APP automatically when connected with your phone, and you can also sync the data to your PC by the supplied cable. Unlimited storage without extra fee. ☀️【Rechargeable and Energy-Saving】 Rechargeable battery runs up to 16 hours after fully charging. There is no button, the device runs automatically when you wear it on and turn off automatically 2 mins after the finger left the probe. If you encounter ERROR FOUR, kindly contact us for solution. ☀️ Scope of delivery: 1X SleepU wrist pulse oximeter；1X USB cable (Micro)；1X User guide