watchOS 4.2.2 (build 15S5530d) is an official Apple over-the-air update for the Apple Watch (42mm), released on 2017-12-13T21:09:02Z. The update package is 49.43 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: 3949c64dc82666f384ad1d61d6598ebc3293b64f.zip.