watchOS 5.2 (build 16T5181f) is an official Apple over-the-air update for the Apple Watch Series 4 (44mm, LTE), released on 2019-01-24T18:08:35Z. The update package is 468.05 MB. This is a delta (partial) update that requires 5.0.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 5c4c3f3611554d04e448429cf4b424e3c2014094.zip.