Vktech&reg; Smart Wristband Sports Sleep Tracking Health Fitness Tracker Smart Wristband Sports & Sleep Tracking Bluetoooth 4.0, IP67 PC cloud service Tracks your daily activity and sleep quality, make your life funnier Built-in USB 2.0, connect it to the PC to sync and get charged. No USB cable needed Built-in rechargeable li-battery, work for up to 4 days after fully charged Automatically sync your data to iPhone 4S, 5, 5S,5C, iPad 3, iPod touch 5, Samsung Galaxy S4 via Bluetooth, visualize your daily activity and sleep quality throughout the day, week or month