watchOS 3.1.3 (build 14S958) is an official Apple over-the-air update for the Apple Watch (42mm), released on 2016-12-21T18:29:47Z. The update package is 126.74 MB. This is a delta (partial) update that requires 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: d7943ddd651f0c18b383ec79b354ff15bbf4f3f0.zip.