watchOS 5.0.1 (build 16R381) is an official Apple over-the-air update for the Apple Watch Series 1 (42mm), released on 2018-09-27T20:08:34Z. The update package is 727.99 MB. This is a delta (partial) update that requires 4.3.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 8683601a89732f8d685dc2fdef574852855ad09b.zip.