The Apple Watch Series 1 Aluminum 42mm was announced in 2016, September. Released 2016, December With 1.65 inches Retina OLED, 450 nits (peak), Powered by Apple S1P (28 nm) and running watchOS 3.0, upgradable to 6.2.8, the device delivered smooth performance and multitasking capabilities. while the Li-Ion 250 mAh (0.94 Wh), non-removable ensured long-lasting usage.