iOS 11.4 (build 15F5049c) is an official Apple over-the-air update for the iPhone 6+, released on 2018-04-16T17:08:17Z. The update package is 218.82 MB. This is a delta (partial) update that requires 11.3 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: a8be4b3e57249ebfd425a0cc05b44b60e611264d.zip.