49mm case size
Flat sapphire front crystal with display edge protection
Certified IP6X dust resistant 
Tested to MIL-STD 810H 
Customizable Action button

Always-On Retina display
Up to 2000 nits brightness
Nearly 27% more screen area than Apple Watch SE

Water resistant 9
Swimproof and recreational dive to 40m
EN13319 certification
Depth gauge with water temperature sensor
Oceanic+ app for use as a dive computer (available on App Store)

Blood Oxygen app
ECG app
High and low heart rate notifications
Irregular rhythm notification 
Cardio fitness notifications

Sleep tracking  

Temperature sensing 
Cycle tracking with retrospective ovulation estimates

Emergency SOS 
International emergency calling
Fall Detection
Crash Detection 
High-g accelerometer
Gyroscope
Compass Backtrack
Siren

Redesigned Compass app with waypoints and backtrack
Precision dual-frequency GPS
Always-on altimeter

Available cellular connectivity
International roaming
Supports Family Setup
  (GPS + Cellular models)
Connect family members who don't have an iPhone

Up to 36 hours
Fast charge