watchOS 5.2 (build 16T5181f) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm), released on 2019-01-24T18:08:05Z. The update package is 438.6 MB. This is a delta (partial) update that requires 5.1.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 517174be78c5a64e38558e17a96667695e98a1f8.zip.