Introducing Apple Watch Series 4. Fundamentally redesigned & re-engineered to help you stay even more active, healthy, and connected. With a large display, electrical heart sensor, re-engineered Digital Crown with haptic feedback Apple Watch Series 4 resets the standard for what a watch can be. ECG on your wrist. Low & high heart rate notifications. Fall detection & Emergency SOS. Breathe watch faces. Its designed to improve your health every day & powerful enough to help protect it.