watchOS 5.2.1 (build 16U113) is an official Apple over-the-air update for the Apple Watch Series 2 (38mm), released on 2019-05-13T17:15:53Z. The update package is 830.08 MB. This is a delta (partial) update that requires 4.2.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: b805166592b9973b169501ff4c8a7f8836e7bfd5.zip.