Product Type: Smart watch Supported Host Device OS: iOS 10 or later, Android 5.0 (Lollipop) or later Notifications: SMS, Email, social apps, incoming calls Navigation: GPS receiver Tracking Data: Distance, calories burned, sleep activity, heart rate, steps taken, blood oxygen saturation, stress level, REM phases Audio Input: Microphone Wearing Style: Watch style Feedback Type: Vibration alert, visual interface Clock Display: Yes Set Goals: Yes Sensors: Accelerometer, ambient light sensor, gyro sensor, SpO2 sensor, 3-axis magnetometer, BioTracker 2 PPG biological tracking optical sensor Features: Making a call, store & play music, huami-PAI Health Assessment System User Memory: 3 GB Type: AMOLED - color Resolution: 454 x 454 pixels Diagonal Size: 1.39" Protection: Fingerprint-resistant coating, tempered glass Pixel Density: 326 ppi Always On Display (AOD): Yes Wireless Interface: Wi-Fi, Bluetooth 5.0 Type: Touch sensitive screen Rechargeable Battery: Yes Capacity: 471 mAh Recharge Time: 2.5 hour(s) Run Time Details: Typical usage - up to 14 days, Basic mode - up to 38 days, GPS mode - up to 48 hour(s), Talk time - up to 10 hour(s) Case Shape: Round Name: Strap Changeable: Yes Clasp Type: Pin buckle Width: 22 mm Material: Leather Color: Obsidian black Details: Case only: 39 g Internet of Things (IoT) Compatible: Yes Intelligent Assistant: Alexa Preloaded Software: Amazon Alexa Vibrating Alert: Yes Body Material: Stainless steel Protection: Water-resistant Included Accessories: Magnetic charging dock Max Depth of Water Resistance: 50 m