watchOS 4.3 (build 15T5212a) is an official Apple over-the-air update for the Apple Watch Series 2 (38mm), released on 2018-03-16T20:09:05Z. The update package is 325.67 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: e3f9d3e059e77cf6b5fc84865432d52070b191f6.zip.