Tips: Before use, please charge the tracker for more than 10 minutes to activate it. Please download and installl App and connect the tracker to your phone via the app. (Do not connect to the device via the phone's Bluetooth settings ) Phone system requirements: iOS 9.0 or higher Android 4.4 or higher Bluetooth 4.0 or higher Sync: Bluetooth 4.2 Working Temperature: 0°F to 104°F Working Time: About 5-7 days USB Charger Requirement: Standard USB port(5V-500mA) Charging Time: 1-2 hours Water Standard: IP68