iPadOS 8.4.1 (build 12H321) is an official Apple over-the-air update for the iPad 4 (Global), released on 2015-08-13T18:05:09Z. The update package is 347.84 MB. This is a delta (partial) update that requires 8.1.3 already installed. This update is currently signed by Apple, so it can be applied from Settings › General › Software Update.

Payload file: fe3b4deb63e1182923d92be3521e35c78699a9fa.zip.