watchOS 4.2.2 (build 15S542) is an official Apple over-the-air update for the Apple Watch Series 3 (42mm, LTE), released on 2018-01-19T18:09:22Z. The update package is 214.89 MB. This is a delta (partial) update that requires 4.0 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 075068e39065516990c54e705c0f61e8abe491ad.zip.