• Temperature sensor provides retrospective ovulation estimates and advanced cycle tracking features⁴ • Measure your blood oxygen with a powerful sensor and app² • Take an ECG anytime, anywhere¹ • Get high and low heart rate, and irregular rhythm notifications¹ • Advanced safety features, including Fall Detection, Emergency SOS⁵, and Crash Detection • Enhanced Workout app with more advanced metrics and ways to train • A completely redesigned Compass app with waypoints and Backtrack • Track your daily activity on Apple Watch, and see your trends in the Fitness app on iPhone • The most crack-resistant front crystal yet on an Apple Watch, IP6X dust resistance and swimproof design, and increased durability for fitness and activity • Call, text, and email with just a few taps • Listen to your favorite music, podcasts, and audiobooks (for use with GPS models) • Make purchases instantly and securely from your wrist with Apple Pay⁷ • Large, Always-On, edge-to-edge display • All-day battery life and fast charging⁸