Series 4 (GPS) Features

Silver aluminum case
Built-in GPS, GLONASS, Galileo and QZSS
S4 with 64-bit dual-core processor
W3 Apple wireless chip
Barometric altimeter
Capacity 16GB 1
Optical heart sensor
Electric heart sensor
Enhanced accelerometer up to 32g force.
Enhanced gyroscope
Ambient light sensor
LTPO OLED Retina display with Force Touch (1000 nits)
Digital crown with haptic feedback.
Louder speaker
Ion-X reinforced glass
Sapphire crystal and ceramic caseback.
Wi-Fi (802.11b / g / n 2.4GHz)
Bluetooth 5.0
Built-in rechargeable lithium ion battery
Up to 18 hours of autonomy 2
Water resistant 50 meters 3
watchOS 5