watchOS 4.3 (build 15T6212) is an official Apple over-the-air update for the Apple Watch Series 3 (38mm), released on 2018-03-29T17:09:47Z. The update package is 154.81 MB. This is a delta (partial) update that requires 4.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 5648614d850d5eab5e93867fbfbc497f593f6a53.zip.