watchOS 5.2 (build 16T5191d) is an official Apple over-the-air update for the Apple Watch Series 4 (44mm, LTE), released on 2019-02-04T18:14:22Z. The update package is 423.29 MB. This is a delta (partial) update that requires 5.1.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: b801c72ec93bdf23ee5ca38e5bcb45ca9e70cfa0.zip.