Silver aluminum case
  
S2 dual-core processor
  
Built-in GPS and GLONASS
  
Water resistant 50 meters2
  
Ion-X glass
  
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