iOS 13.3.1 (build 17D5044a) is an official Apple over-the-air update for the iPhone 11 Pro Max, released on 2020-01-14T18:21:10Z. The update package is 244.64 MB. This is a delta (partial) update that requires 13.3.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 66e37aaafd4bdf2c5dd875220bb9c2305d03bd5a.zip.