Apple Watch Ultra 3 is designed for demanding fitness, outdoor, and everyday use. Its 49mm titanium case includes a bright Always-On Retina display reaching up to 3000 nits. It provides advanced health and fitness features, ECG, sleep tracking, GPS, fall and crash detection, a siren, water resistance to 100 metres, a depth gauge, water-temperature sensing, precision dual-frequency GPS, and fast charging. Battery life is rated up to 42 hours, or up to 72 hours in Low Power Mode.