watchOS 6.1 (build 17S5054e) is an official Apple over-the-air update for the Apple Watch Series 4 (44mm, LTE), released on 2019-09-23T17:05:01Z. The update package is 254.51 MB. This is a delta (partial) update that requires 6.0 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: f53182ad4906fd4e761fcd7bb8e4547f0275dfcd.zip.