watchOS 4.2.2 (build 15S5536a) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm), released on 2018-01-03T18:22:37Z. The update package is 77 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: ee438fb0b2ad369514b6114f5ce88a4690e8484b.zip.