Stay connected, healthy, and safe with the Apple Watch Series 5. You interface with all of the Series 5's features and the watchOS through its 40mm curved watch face with an LTPO OLED always-on Retina display. With an always-on screen in low-brightness, you can quickly glace at the watch face for the time, workout stats, and more. If you lift your wrist, the screen will automatically come back to full brightness. The case also features a digital crown with haptic feedback, and a heart rate monitor that's capable of recording your own ECG.