OS & Configuration: Runs on Android 7.1 OS, powered by high-performance MTK6739 Quad-core CPU. 1GB RAM+16GB ROM (or 3GB RAM+32GB ROM optional) ultimately deliver a richer using experience. Built-in Nano SIM Slot: Supports independent 4G call function. Just plug in your Nano SIM card to make a call directly, no need to carry your mobile phone when exercising. Pedometer & Heart Rate Monitoring: Intelligently calculate your motion steps and distance, taking care of your health. Supports recording your heart rate to keep abreast of your physical condition. HD Screen: 1.88-inch round touchscreen with a resolution of up to 320*360p, the picture is smooth and clear, stylish and cool without losing vitality. More Convenience: Supports BT, GPS navigation and WiFi. With built-in big speaker, you can enjoy music whenever and wherever you want. 5MP HD camera records every good moment.