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 600.74 MB. This is a delta (partial) update that requires 3.1.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: da8df880b8b2ffd01d689c5980b08af0781513d1.zip.