watchOS 4.2.2 (build 15S5540a) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm), released on 2018-01-09T18:13:33Z. The update package is 150.69 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: 09fccf711c16577fb96de8ba341bae0a81c3002a.zip.