watchOS 5.3.5 (build 16U652) is an official Apple over-the-air update for the Apple Watch Series 4 (44mm), released on 2020-02-18T18:07:09Z. The update package is 55.62 MB. This is a delta (partial) update that requires 5.3.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 936a66772202b7b7baa10d1ed64a61c627cff11d.zip.