General Watch Operating System watchOS 2 Compatible Operating System iOS 8.2 and later Chipset Not Specified By Manufacturer RAM Not Specified By Manufacturer Storage Capacity 8 GB Sensors Accelerometer, Gyroscope, Heart Rate, Light Sensor Activity Tracker Yes Microphone Yes Built-in Speaker Yes Vibration Yes Connectivity Connectivity Bluetooth, Wi-Fi, NFC Bluetooth Protocol Bluetooth LE Bluetooth Version 4.0 Wi-Fi Standard 802.11b/g/n GPS No Display Dial Shape Rectangle Dial Size 1.5" / 38.1 mm Dial Type Digital Display Technology OLED Display Resolution 312 x 390 pixels Pixel Density 302 ppi Battery Battery Type Not Specified By Manufacturer Battery Capacity Not Specified By Manufacturer Battery Life Normal Use: Up to 18 hours Music: Up to 6.5 hours Standby: Up to 48 hours Power Saver: Up to 72 hours Battery Charging Time 2.5 hours Charging Method Magnetic Connector Physical Watch Crystal Material Aluminosilicate Glass Case Materials Aluminum