The Apple Series 4 smartwatch runs on a powerful S4 dual-core processor that delivers fast and efficient performance. The watchOS 5 operating system efficiently handles all hardware and software of this smartwatch. The W3 wireless chip boosts the performance of WiFi. With optical heart sensor, this Apple smartwatch keeps an accurate track of your heart rate. New dual-core processor for faster performance. Track your progress of workouts, calories burnt and heart rate. Customize your watch face with information for quick access. It offers complete water resistance up to 50 meters. Features 16 GB internal memory.