watchOS 4.3 (build 15T5199f) is an official Apple over-the-air update for the Apple Watch Series 2 (38mm), released on 2018-03-06T18:07:59Z. The update package is 346.31 MB. This is a delta (partial) update that requires 4.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: eb99f3796a5086602efd0ae95f5a39e5ae558549.zip.