Stainless steel case S2 dual-core processor Built-in GPS and GLONASS Water resistant 50 meters2 Sapphire crystal 2x brighter OLED Retina display with Force Touch (1000 nits) Ceramic back Digital Crown Heart rate sensor, accelerometer, and gyroscope Ambient light sensor Direct fire speaker and microphone Wi-Fi (802.11b/g/n 2.4GHz) Bluetooth 4.0 Up to 18 hours of battery life3 watchOS 3