- 45mm or 41mm -Swimprooffootnote
- Most crack-resistant front crystal
- Certified IP6X dust resistantfootnote
- Always-On Retina display
- Nearly 20% larger than SE
- More than 50% larger than Series 3
- Blood Oxygen app -ECG app
- High and low heart rate notifications
- Irregular heart rhythm notification
- Emergency SOS
- International emergency calling
- Fall detection
- Family Setup
- pair multiple watches with one iPhone