iPadOS 8.4 (build 12H143) is an official Apple over-the-air update for the iPad mini 3 (China), released on 2015-06-30T15:51:15Z. The update package is 428.01 MB. This is a delta (partial) update that requires 8.1.1 already installed. This update is no longer signed by Apple, meaning it can no longer be applied on-device through Settings.

Payload file: 4a2c785b36c4b746227f8725e1a34f08063888f1.zip.