Take calls and reply to texts, right from your wrist - Up to 20% faster than the previous Apple Watch SEAdvanced safety features, including Fall Detection, Emergency SOS, and Crash Detection - Track your daily activity on Apple Watch, and see your trends in the Fitness app on iPhoneEnhanced Workout app with more advanced ways to train - Get high and low heart rate and irregular rhythm notifications - Listen to your favorite music, podcasts, and audiobooks (for use with GPS models)Make purchases instantly and securely from your wrist with Apple Pay - Swimproof design - Sleep stages tracking lets you see how much time you spend in REM, core, and deep sleep