Long Battery Life: The Duobuy Smart Ring has a battery life of up to 3-5 days on a 2 hrs charge. We offer a free portable charging case with 400 mah battery, it can fully charge the smart ring for about 15 times, which greatly extending the usage time to 60 days. Ideal for frequent business travelers and outdoor enthusiasts, ensuring continuous health monitoring no matter where you are.Activity Tracker & Multiple Sport Modes: The fitness rings for women automatically track your steps, calories burned and distance throughout the day. This smart ring has multiple sports modes such as running, cycling, skipping rope, walking, hiking, yoga, dancing, golf and more. Active these sport modes, you will get workout route, sport time, steps, heart rate, speeds, calories burned and distance from the App, to provide you with more effective exercise guidance.Track Your Health from Your Finger: This slim vital health ring for women provides 24-hour blood oxygen, 24-hour heart rate and 24-hour blood pressure monitoring. You can conveniently view these real-time health indicators from your wrist any time, any where, and You can view daily, weekly and monthly health data in the App. Duobuy vital health ring for women provides you a more accurate monitoring information to help you explore a healthier lifestyle.Size Before You BuyBefore purchasing the Duobuy Smart Ring, we highly recommend to buy the Duobuy Sizing Kit to determine the most comfortable and suitable size for your finger, avoiding the inconvenience of returns and exchanges. The Duobuy Smart Ring is designed according to the US ring standard, If you know your ring size in US measurements, you can choose to purchase our smart ring using the same US ring size.Easy to Charge and Wide Compatibility: Simply charge the smart rings for women with a magnetic USB cable or the charger case. The smart rings for women are compatible with Android 4.4 / iOS 8.4 or above smart phones. What you get includes: Duobuy smart ring *1, 400mah charger case*1, magnetic USB charge cable*1, type C charge cable*1 and instruction*1. This ring tracker is a great gift for women.Intelligent Sleep Tracker: Your favorite sleep tracker is now wrapped around your finger. this health rings for women can also automatically monitor your sleep. Monitor your falling asleep, waking up time, sleep quality (deep sleep and light sleep) through graphs. You can view daily, weekly and monthly sleep data in the App, helping you better adjust your habits to improve your sleep quality. Fitness ring is so comfort, you wont even notice its there while it monitors your sleep.NO Subscription Fees: After purchasing the Duobuy vital ring, you can enjoy lifetime free access to the smart health application. Enjoy real-time health tracking around the smart ring without any extra fees. No subscription fees to download the App and use it for lifetime. If you know your ring size, then you don't need to measure the size in our way, our smart ring is designed according to the US ring size standard.