watchOS 4.2.2 (build 15S542) is an official Apple over-the-air update for the Apple Watch Series 1 (38mm), released on 2018-01-19T18:08:50Z. The update package is 559.18 MB. This is a delta (partial) update that requires 3.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: d723480110f84278a7bd0c8468b89d1a9fad5100.zip.