watchOS 4.3 (build 15T5176c) is an official Apple over-the-air update for the Apple Watch Series 2 (42mm), released on 2018-02-07T18:09:40Z. The update package is 316.28 MB. This is a delta (partial) update that requires 4.2 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: aa61edc2999360f9ad5a265d5e44278c75ef4013.zip.