watchOS 4.2.2 (build 15S5536a) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm, LTE), released on 2018-01-03T18:22:28Z. The update package is 103.38 MB. This is a delta (partial) update that requires 4.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: d3819ab22fde29f4c3afc813d3ba99dc7383f0b8.zip.