watchOS 5.2.1 (build 16U5113a) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm), released on 2019-05-07T17:19:15Z. The update package is 144.89 MB. This is a delta (partial) update that requires 5.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 555e09a6b46dd4c3e56103125e9265cd60cbc98b.zip.