watchOS 5.2.1 (build 16U6113) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm, LTE), released on 2019-05-13T17:17:02Z. The update package is 88.92 MB. This is a delta (partial) update that requires 5.2.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 43eb24d68f2eb6b328a655f6092fe1a70a583c7b.zip.