watchOS 5.3 (build 16U5569a) is an official Apple over-the-air update for the Apple Watch Series 2 (42mm), released on 2019-07-16T17:14:09Z. The update package is 169.78 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: f4ac0d362795f6d0f3eb2d1ab734649477f255c5.zip.