Apple Watch Ultra 4: same sensors as the Series 12, but 50-hour battery life and certified diving
The Apple Watch Ultra 4 shares sensors with the Series 12 and sets itself apart through battery life: 50 hours of use, 45 hours of extended workout, certified diving, and satellite.
Apple Watch Series 12: heart rate every 5 seconds, Readiness, and one detail in the glass
The Apple Watch Series 12 measures heart rate 60 times more often and introduces Readiness. Price, specs, and why Ceramic Shield 2 is only on aluminum.
