Compatibility: Support all devices with Android 4.4 or later (Bluetooth 4.0 or later), iOS 7.1 or later; Download app "VeryFitPro" from Apple Store or Google Play for free, or you can scan QR code on the user manual to download Functions: Step Pedometer, Distance, Calories Burned, Sleep Monitor, SMS Alert, Sedentary Reminder, Call Alert (Caller name & Caller ID), Alarm Alert, Camera Remote Control, Find Your Phone, Anti-lost, etc. Activity Tracker: This smart bracelet can track your all-day activities, including steps, distance, calories, etc. You can read the data on the smart bracelet; Automatically track your sleep state, help you know your sleep quality by the provided data like deep sleep hours, light sleep hours, awake hours, etc. Long Standby Time: Built-in USB plug makes it easy to charge in any USB port; Battery: Built-in 45mAh Rechargeable Li-Polymer Battery; Charge time: 1-2 hour; Standby Time: 5-10 days Waterproof IP67: You can wear it while exercising, swimming in the pool, washing your hands, etc. But do not use it in diving, showering, seawater or water vapor environment