watchOS 4.2.2 (build 15S5540a) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm, LTE), released on 2018-01-09T18:13:20Z. The update package is 1.57 GB. This is a full OTA update that can be applied from any compatible base version. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 9b47cf1a066f926f6d5e6a337ec707adba71a1a3.zip.