Fundamentally redesigned and re-engineered, the largest Apple Watch display yet features a built-in electrical heart sensor, a new Digital Crown with haptic feedback, and low and high heart rate notifications. It includes fall detection and emergency SOS, along with new Breathe watch faces and automatic workout detection. There are new yoga and hiking workouts, advanced features for runners like cadence and pace alerts, and new head-to-head competitions. Activity sharing with friends, personalized coaching, monthly challenges, and achievement awards are also included. Built-in cellular connectivity allows you to use Walkie-Talkie, make phone calls, and send messages. You can stream Apple Music and Apple Podcasts and use Siri in all-new ways, even while away from your phone. With Apple Watch Series 4, you can do it all with just your watch.