watchOS 4.2.2 (build 15S5536a) is an official Apple over-the-air update for the Apple Watch Series 1 (42mm), released on 2018-01-03T18:22:23Z. The update package is 145.1 MB. This is a delta (partial) update that requires 4.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 1bb6ebb9e7d2137890130a80bfebdba1f110a503.zip.