watchOS 5.3 (build 16U5526f) is an official Apple over-the-air update for the Apple Watch Series 2 (42mm), released on 2019-05-15T17:11:17Z. The update package is 451.58 MB. This is a delta (partial) update that requires 5.1.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 38ad5f5794e0d1471d241f2d951b14b5162f58ef.zip.