watchOS 4.2.2 (build 15S5530d) is an official Apple over-the-air update for the Apple Watch Series 3 (42mm), released on 2017-12-13T21:09:52Z. The update package is 60.45 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: ffa2d0c0348103a5462d8baa0c6ea04f041da885.zip.