watchOS 5.3.4 (build 16U627) is an official Apple over-the-air update for the Apple Watch Series 4 (44mm), released on 2019-12-10T18:22:28Z. The update package is 55.54 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: e2b7e2729e1f128a7d209378aacf51ce8bdfb367.zip.