watchOS 6.1 (build 17S5076a) is an official Apple over-the-air update for the Apple Watch Series 4 (44mm, LTE), released on 2019-10-16T17:13:56Z. The update package is 747.06 MB. This is a delta (partial) update that requires 5.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: e6a028e8f1fb6439516a8b397e06b66f7275eb7e.zip.