watchOS 5.2.1 (build 16U113) is an official Apple over-the-air update for the Apple Watch Series 4 (44mm), released on 2019-05-13T17:17:59Z. The update package is 140.42 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: ed5c17ab5735415e1cec8fc3772e93766d0fe784.zip.