Apple Watch Sport features

gold anodized aluminum case
Ion-X glass
Retina display with Force Touch
Composite back
Sport Band with stainless steel pin
Digital Crown
Heart rate sensor, accelerometer, and gyroscope
Ambient light sensor
Speaker and microphone
Wi-Fi (802.11b/g/n 2.4GHz)
Bluetooth 4.0
Up to 18 hours of battery life*
Water resistant**
Apple Watch may ship with watchOS. But watchOS 2 is available as a free download.
What’s in the box
Apple Watch
Magnetic charging cable (2 m)
USB power adapter (5W)
Sport Band (includes band that can be configured for either S/M or M/L length)
Quick start guide
Dimensions

Height: 42.0mm
Width: 35.9mm
Depth: 10.5mm
Case: 30g